- Email: [email protected]
Congenital deafness and goiter
Congenital
Deafness
and Goiter*
Studies of a Patient With a Cochlear Defect and Inadequate Formation of Iodothyronines CHARLES S. HOLLANDER, M.D.,~ THADDEUS E. PROUT, M.D., MACCALLUM RIENHOFF, M.D.,$ ROBERT
J.
RUBEN, M.D. t and SAMUEL P. ASPER, JR., M.D. Baltimore, Maryland
G
OITERassociated with deafness was recognized by Bueno [7] in 1769, Wood [I] in 1824 and Pendred [Z] in 1896 and is referred to as Pendred’s syndrome. The defect in the synthesis of thyroid hormone in goitrous deaf patients has been characterized as a failure of iodination of tyrosine [3-51. The nature of the hearing loss in these patients has not been extensively studied. This report consists of a study of a patient with goiter and deafness whose abnormality in formation of the thyroid hormones, in contrast to previously described patients, was due to a defect other than inadequate iodination of tyrosine and whose deafness, studied by recently improved procedures [6], was due to a defect in cochlear reception.
CASEREPORT The patient (A. M. J., No. 101 03 76) was a twentyeight year old Negro mother of six children. She was admitted to the Johns Hopkins Hospital for evaluation of goiter and deafness. The mother of the patient had a large goiter which was first noted at about twenty years of age. The patient has seven siblings of whom only two were available for examination. They were clinically euthyroid with normal hearing, but one of them, a thirty-five year old sister, had a diffuse uniform enlargement of the thyroid gland to about four times normal size. The only child of the patient’s first marriage was said to have normal hearing and a goiter, but neither this child nor her first husband was available for examination. Her second husband was deaf from birth but had no goiter. Two sons and one daughter of the second marriage are deaf; two other children of this marriage have normal hearing. A deaf male child and a female child with normal hearing were examined, and neither had a goiter.
The patient was born in North Carolina; she is congenitally deaf with associated mutism although she can enunciate a few words. She reached the eleventh grade at a state school for the deaf. At the age of twenty-six, two years prior to admission, the patient noted the onset of dysphagia. Simultaneously she became aware of an asymmetric enlargement of her neck, greater on the right side. She had no symptoms of hyperthyroidism or hypothyroidism. Six months prior to admission she complained of pain and tenderness in her neck for a period of several weeks. The pain subsided, and upon admission her only symptom was moderately severe dysphagia. The patient had not taken iodine, desiccated thyroid or any known goitrogen. Physical examination revealed an intelligent, cooperative woman of healthy appearance with normal temperature, blood pressure of 122/84 mm. Hg and pulse rate of 72 per minute. The respirations were regular at 16 per minute. She was deaf. The tympanic membranes appeared normal. Her thyroid gland was diffusely enlarged, the right lobe being approximately five times normal size and the left lobe twice normal size. No nodules were felt. There was no thrill or bruit over the gland. She had incurved fifth fingers bilaterally (clinodactyly). The skin, eyes, reflexes and remainder of the examination were within normal limits. Laboratory examinations revealed a hematocrit of 42 per cent and a hemoglobin of 12.4 gm. per 100 ml. The total white blood cell count was 5,250 per cu. mm. with 52 per cent polymorphonuclear leukocytes, 35 per cent lymphocytes, 4 per cent basophils, 3 per cent monocytes and 6 per cent eosinophils. Urinalysis was normal with a specific gravity of 1.013. The serum levels of urea nitrogen, fasting blood sugar, carbon dioxide-combining power, chloride, phosphorus, sodium and potassium were normal. The results of other tests were as follows: cephalin floccula-
* From The Departments of Medicine an-l Surgery, The Johns Hopkins University, Baltimore, Maryland. This study was supported in part by Grant A-2041 from the U.S. Public Health Service. Manuscript received September II, 1963. 7 Present address: National Institutes of Health, Bethesda, Maryland. $ Present address: Department of Pathology, University of Colorado Medical School, Denver, Colorado. 630
AMERICAN
JOURNAL
OF
MEDICINE
Congenital Deafness and Goiter-Hollander TABLE DISTRIBUTION
-
OF I’31
Comnonent Condition
Subject
Dose (PC.)
1 2 3 4 5 6 7 8 9 10*
Nongoitrous Nongoitrous Nontoxic goiter Nontoxic goiter Nontoxic goiter Colloid adenoma Colloid adenoma Colloid adenoma Colloid adenoma Congenital goiter and deafness
300 200 200 200 200 200 200 200 200 100
631
1
IN THE HUMAN THYROID
Time After I’31
1131
et al. GLAND
of Thvroid Hormone total radioactivity)
(% of
-
I Ratio of Monoiodotyrosine Diiodotyrosine
-
(hr.)
Monoiodotyrosine
Diiodotyrosine
Triiodothyronine
Thyroxine
45 48 24 48 48 24 48 48 72
32.6 25.1 29.3 49.5 33.4 34.8 38.0 28.7 31.9
47.3 58.6 63.6 34.5 59.6 60.0 50.5 60.3 55.4
0.5 ... 0 0 0 < 0.5 0 < 0.5 0
10.1 9.1 2.2 5.4 4.7 1.1 2.4 3.5 6.0
0.69 0.48 0.46 1.40 0.56 0.50 0.75 0.48 0.58
56
87.0
13.0
0
0
6.50
-
:
-
NOTE: Ten subjects, either healthy or with thyroid disorders as shown, were given radioiodine orally and later, at subto:al thyroidectomy, tissue was taken for analysis of radioiodine in various components of the thyroid hormones, thyroxine and triiodothyronine, and their precursors, monoiodotyrosine and diiodotyrosine. * Patient A. M. J.. tion 2+ at 48 hours, thymol turbidity 9.2 units, serum cholesterol 250 mg. per cent, serum proteins 6.7 gm. per cent of which 5.0 gm. was albumin and 1.7 gm. was globulin, serum bilirubin 0.8 mg. per cent, and alkaline phosphatase activity 3.0 Eodansky units. The retention of bromsulfalein was 3 per cent at 45 minutes. Hemoglobin was normal by electrophoresis, and the lupus erythematosus cell preparation and results of a serologic test for syphilis were negative. The mastoids were normal on roentgenogram. The chest roentgenogram and the scintiscan of the thyroid gland showed the upper portion of the trachea to be moderately displaced to the left by a markedly enlarged right lobe of the thyroid gland. The serum protein-bound iodine and the butanolextractable iodine were 6.0 and 4.6 pg. per cent, respectively. The radioiodine uptake by the thyroid gland was 41 per cent at 2 hours and 39 per cent at 24 hours. Other special studies of thyroid function are reported subsequently. Studies of vestibular function were normal. Chromosomal studies showed a normal idiogram consisting of 46 chromosomes. A subtotal thyroidectomy was performed. The entire right lobe, containing a large nodule, and most of the left lobe were removed. The excised tissue weighed 160 gm., and approximately 40 gm. of tissue was left in situ. The bulk of the tissue was used in special studies to be reported. Histologic sections of the nodule and surrounding tissue were examined. The nodule was composed of macrofollicles containing colloid; the tissue surrounding the nodule was hyperplastic. VOL..
37,
OCTOBER
1964
METHODS AND MATERIALS Several studies were conducted prior to subtotal thyroidectomy. Radioiodine (20 PC,) was administered orally to the patient, and the thyroidal uptake was measured at intervals. When the radioiodine reached a relative plateau in the thyroid gland, the patient was given 1.8 gm. potassium thiocyanate orally. On a second occasion 1.0 gm. of potassium perchlorate was employed. The emanations from the thyroid gland were measured by a Baird-Atomic@’ detector which activated an Esterline-Angus@ recorder. The detector was equipped with a collimator to minimize the background interference. Background readings were made without moving the patient by inserting a lead shield into a holder placed between the thyroid gland and the counter. Continuous counts were recorded for two hours after the administration of both potassium thiocyanate and potassium perchlorate. The purity of monoiodotyrosine,* labeled with Ii3i (approximately 3.22 PC. per mg.), was demonstrated chromatographically. An amount containing 50 PC. of Ii3’ was administered orally to the patient and to one normal subject. Fractional urine collections were obtained 2, 4, 6 and 24 hours thereafter. Serum was obtained from the goitrous subject at 48 hours. The protein-bound I*ri was then determined by two methods. In the first, 5 ml. of serum was subjected to trichloracetic (5 per cent) precipitation, and the amount of radioactivity remaining with the washed * Abbott Laboratories,
North Chicago,
Illinois.
Congenital Deafness and Goiter-Hollander
632
IBgm.
et al.
KSCN
+
Q-_-Q--*
_,__Q___Q--
---___
KSCN
___________________~
,..-a ,/& __&__------+-*-_____ .‘a
,* ,/’
‘““P
Kc’o4 0
-C-s-------
*------____
------_______*
y’
KC104
IO’
,d (// t__~_,____________________-_-___-----------------------.’
: 8’
’
i
_____---x---
------_
__-_____-__--__-x________I
;
Control
I
,’ I’
:
,1
/’
: :
,I’
,’
,’
: +
TEST
I- 131
/’ I’
:
_--
_.*-
:
:
I I( ! ’ I’
5 UC
x-----x
Control
20 UC
o-----o
KSCN
l.Swn.
24~
e-----e
KC104
I.Ogm.
I
:: If
30
m
90
120
150
130
210
*4PGz
TIME IN MINUTES FIG. 1. Patient A. M. J. with congenital deafness and goiter. The radioiodine content, recorded as counts per minute, of the thyroid gland during three separate 24-hour tests. Neither potassium perchlorate (KCIOI) nor potassium thiocyanate (KSCN) caused release of radioiodine from the gland. This indicates that the gland of this patient was able to iodinate tyrosine. Radioiodine was given orally at time zero. precipitate was measured. In the second, 5 ml. of serum was passed through an anion exchange resin to adsorb free iodine (Amberlite IRA 400@) and the residual amount of radioactivity determined. T’he thyroid glands of the goitrous deaf patient, seven patients with goiter and two normal subjects were removed. All had received doses of Ir3r varying from 100 to 300 PC. 24 to 72 hours before surgery. (Table I.) Extracts of thyroid [7], serum [8] and urine [9] were concentrated in a flash evaporator and subjected to descending chromatography on filter paper. In all instances, standard solutions of monoiodotyrosine, diiodotyrosine, iodine, L-thyroxine and triiodothyronine were used as markers. The solvent systems used were: n-butanol-acetic acid (2N)-water (450: 50: 125 v/v), n-butanol saturated with 2N ammonium hydroxide, n-butanol-dioxane-ammonia (2N) (80: 20: 100 v/v) and tertiary amyl alcohol saturated with 2N ammonium hydroxide [ 701. Chromatography was performed in duplicate on
each sample. One of the chromatograms was stained with a solution of ceric sulfate-arsenious acid [a]. The other chromatogram was dried, cut into 0.5 cm. strips, placed in plastic test tubes and the amount of radioactivity measured in a Baird-Atomic well-type scintillation counter. Studies of the labyrinth were carried out in the deaf patient four weeks after thyroidectomy. The vestibular apparatus was tested by means of Barany chair rotation and cold caloric stimulation. Hearing studies were carried out with routine pure tone audiometry, bone conduction, speech discrimination and psychogalvanic skin resistance. Following the routine studies, direct measurements of cochlear function were made. Details of this procedure have been published previously [6,77]. Under general anesthesia, the tympanic membrane was reflected and a small electrode was placed in the round window niche. The round window responses were amplified and recorded while the ear was being stimulated by pure tones and clicks. The maximum AMERICAN
JOURNAL
OF
MEDICINE
Congenital
Deafness
and Goiter--H&m&r
et ul.
633
Iodide It--H Total Counts:3,763
mo
600 0) 2 izi500 ti CL I.0 E2 400 u '; z 300
200 MIT 1-1
DIT Ic---*l
$&
100 < 7c
Centimeters
FIG. 2. Patient ‘4. M. J. with congenital deafness and goiter. Graphic representation of data obtained by paper chromatography of urine collected from the sixth through the twenty-fourth hour following administration of monoiodotyrosine Ii3r. The radioactivity excreted was entirely iodide. This indicates a normal mechanism for deiodination of tyrosine. Keference positions for monoiodotyrosine (MIT), diiodotyrosine (DIT), triiodothyronine (Ta) and thyroxine (T~J in this solvent system are shown. intensity decibels.
used
for
pure
tone
stimulation
was
100
RESULTS
‘l’he goitrous deaf patient was given radioiodine to determine whether the gland had normal mechanisms for concentrating iodine (“trapping”) and for iodinating tyrosine (“organification”) [3]. Evidence that the gland was able to concentrate iodide was obtained by demonstration that 41, 40 and 39 per cent of the administered Ii3i was taken up by the gland at 2, 4 and 24 hours, respectively. On separate occasions the patient was given radioiodine followed by potassium thiocyanate or potassium perchlorate as shown in Figure 1. The thyroid gland failed to release the Ir3i on both occasions. Radioiodine which had not been converted to the tyrosyl constituents of the gland would have been discharged from the gland by these agents. VOL.
37,
OCTOBER
1964
Monoiodotyrosine-Ii3i was administered orally to the patient and to one normal subject. Fractional urine specimens were collected from each subject at 2, 4, 6 and 24 hours. Chromatography of the urine extracts, performed in three solvent systems, revealed that Ii31 was excreted in both subjects. These results establish that the patient (Fig. 2) has a normal ability to deiodinate monoiodotyrosine. The patient was given 100 PC. of InSi, and serum samples were collected at 24 and 48 hours and at the time of subtotal thyroidectomy (56 hours). In all three samples, at least 94 per cent of the amount of radioactivity contained in the serum was butanolextractable. The concentrated butanol extract was chromatographed in butanol-ammonia and tertiary amyl alcohol-ammonia solvent systems. In butanolammonia solvent, 90 per cent of the amount of radioactivity migrated to the area of thyroxine and approximately 10 per cent to that of triiodothyronine. No radioactivity was detectable in the areas of diiodo-
634
Congenital
1
Deafness and Goiter--HoZZunder et al.
24
Total Countsl20;175
Totai Counts:1,665
Centimeters FIG. 3. Patient A. M. J. with congenital deafness and goiter. Graphic representation of data obtained by paper chromatography of serum obtained 24 hours after administration of radioiodine is shown. The radioactivity present was found to be in thyroxine or triiodothyronine. No other iodinated compounds were found. Explanation of abbreviations is given in Figure 2.
tyrosine or monoiodotyrosine. (Fig. 3.) In the tertiary amyl alcohol-ammonia system a better separation of thyroxine and triiodothyronine was achieved, and 97 per cent of the amount of radioactivity was localized to the area of thyroxine. Saline extracts of the butanol-insoluble fraction of the serum were also chromatographed in these solvent systems; the radioactivity of this material was not localized to any specific area. The protein-bound 1”’ was determined by two different methods upon 5 ml. of the serum collected at 48 hours. In both instances a high normal value of 0.4 per cent was obtained. The bulk of the gland obtained at operation was subjected to tryptic digestion. Butanol extracts of the hydrolysate were concentrated and chromatographed in two solvent systems. The amounts of monoiodotyrosine and diiodotyrosine found indicated that adequate digestion of the gland had been obtained. No thyroxine or triiodothyronine was present in the concentrate obtained from 100 gm. of thyroid gland. Although the ratio of monoiodotyrosine to diiodotyrosine varied in the different solvent systems, the differences were slight, and the ratio was approximately 6.5 to 1. (Fig. 4.) The distribution of radioactivity in the thyroid
gland of this patient is shown in Table I with results of similar studies in other subjects. In nontoxic goiter and in colloid adenomas the amounts of thyroxine-P in the gland at 48 hours ranged from 2.4 to 5.4 per cent; whereas none was found in the patient. The vestibular studies revealed normal function. All of the audiometric studies revealed a total hearing loss. Occasionally, there would be some response at 1,000 cycles with an 85 decibels sound intensity; this response, however, was not consistent and probably represents tactile appreciation. The middle ear was normal. Recordings at the round window niche revealed total absence of cochlear potentials and eighth nerve action potentials. COMMENTS
A specific defect in the synthesis of thyroxine has been defined in five types of familial goiter. First, goiter may be caused by inability of the thyroid gland to trap iodide [ 72,731. Secondly, goiter may also be produced if the thyroid gland is unable to convert inorganic iodide into an organic form [74,75]. This latter defect in thyroxine synthesis can be recognized by the AMERICAN
JOURNAL
OF
MEDIOINE
Congenital Deafness and Goiter--H&n&r
et al.
635
Iodide
Centimeters
FIG. 4. Patient A. M. .I. with congenital deafness and goiter. Graphic representation of data obtained on paper chromatography of an extract of the thyroid gland obtained 56 hours after oral administration of In1. A portion of the extract that was presumabIy not completely enzymatically digested remained at origin as shown. The ratio of total units of monoiodotyrosine In1 to diiodo6.5 to 1. No measurable amounts of either tyrosine I13i was approximately thvroxine I’si or triiodothvronine Ii3’ were found. Explanation of abbreviations ,is given in Figure 2.
characteristic release of labeled iodine from the thyroid gland when either perchlorate or thiocyanate is administered. A similar and closely related type exists in deaf patients with a less severe defect in iodination of tyrosine [4,5]. The deafness in these patients is also familial. Although it was presumed initially that the patient had this type of defect, the studies revealed that her gland did not contain significant amounts of free I13’. It was concluded that she did not have a defect in the ability either to accumulate iodine or to iodinate tyrosine. Two other metabolic defects causing familial sporadic goiter are impaired dehalogenase activity [76] and the synthesis of abnormal iodoproteins [77]. Since all of the monoiodotyrosine-Ill3 administered to this patient was ex“01..
37,
OCTOBER
1964
creted as free iodide, it was concluded that dehalogenase activity was normal. In the butanol extract of the serum following administration of 113’ to the patient, over 90 per cent of the amount of radioactivity was in thyroxine, and the remainder was in triiodothyronine; no monoiodotyrosine, diiodotyrosine or abnormal iodinated thyroid proteins were detected. Moreover, 94 per cent of the amount of radioactivity in the serum was butanol-extractable, and no abnormal iodoprotein could be detected upon chromatography of saline extracts of the butanolinsoluble fraction of the serum. The fifth and remaining defect of thyroxine synthesis to be considered is an impaired condensation of iodotyrosines to produce iodothyronines [78]. The goitrous deaf patient of this study was given 100 PC. of 1131 56 hours prior to
636
Congenital Deafness and Goiter-Hollander
subtotal thyroidectomy. Following surgery the excised portion of the gland was subjected to tryptic hydrolysis, extraction, concentration and chromatography. Monoiodotyrosine and diiodotyrosine were present in a ratio of 6.5 to 1, and no thyroxine or triiodothyronine was detectable. This patient was the only one among the ten subjects (two normal and eight goitrous) studied who had no iodothyronines in the thyroid gland. In patients with nontoxic goiter or with colloid adenoma the amount of thyroxine in the thyroid gland was less than that found in two normal subjects. Others have found the level of the iodothyronines to be low in patients with colloid goiter [79,20]. In this study the ratios of monoiodotyrosine to diiodotyrosine in the patients with nontoxic goiter and colloid adenoma were similar to those found in the normal subjects. The absence of iodothyronines in our patient is not simply a result of slow formation of triiodothyronine and thyroxine from a sluggish, colloid filled gland. Adequate time was allowed for the synthesis of iodothyronines as shown by the ability of other patients with colloid goiter to synthesize reduced but readily measurable quantities of iodothironines within 48 hours. Moreover, the high normal protein-bound 1131 value indicated that there is a small pool of 1131 within the gland turning over rapidly to permit the achievement of a eumetabolic state. On the basis of these observations it is postulated that our patient has a partial defect in the condensation of iodotyrosines. It is not possible to define this defect by a single simple laboratory test, The diagnosis is based on the chromatographic analysis of the labeled materials in the thyroid gland following oral administration of I 131. In such persons labeled iodotyrosines are found in great abundance, and labeled iodothyronines are absent. The prevailing hypothesis to account for these findings is the absence of a factor necessary for formation of the ether linkage of the thyronines. Although an enzymatically controlled process of condensation has been postulated, no enzyme capable of catalyzing this reaction has been demonstrated in mammalian thyroid tissue. Alternative hypotheses include the following: (1) steric interference with approximation of the tyrosyl constituents; (2) competitive inhibition of condensation by abnormal tyrosyl derivatives; and (3) defective formation of diiodotyrosines, as shown by the high ratio of monoiodotyrosine to
et al.
diiodotyrosine with consequent impedance of thyroxine formation. Available technics do not permit differentiation among these alternatives. Whatever the mechanism for the failure of thyroxine synthesis, the severity of the defect may vary from one patient to another. For example, of five patients recently described, three were hypothyroid and retarded [21,22], whereas two others were euthyroid [78]. The goitrous deaf patient in the present study also was euthyroid and had normal levels of thyroxine and butanol-extractable iodine in the blood. Since no thyroxine was found in her gland and an adequate quantity was present in serum, it appears likely that the thyroxine formed despite the partial defect was rapidly released from the gland. The patient had normal vestibular response but no hearing. The absence of the cochlear potential and the eighth nerve action potential indicates that the hearing loss is secondary to disease of the organ of Corti, probably related to the lack of hair cells. The patient then has a normal vestibular apparatus, crista, utricle and possibly saccule, and a diseased cochlea. The relationship of the patient’s thyroid defect to her deafness is uncertain. Specific cochlear deafness, first described by Siebenmann, according to Batsakis and Nishiyama [23], was noted in association with endemic goiter in the Swiss Alps. Section of the temporal bones at autopsy of these patients revealed degeneration of the organ of Corti and of the macula of the saccule. The crista of the semicircular canals and the macula of the utricle were found to be intact. The patient described herein has a definite cochlear lesion; whether this is the exact lesion described by Siebenmann cannot be determined. Study of other patients with goiter and deafness with carefu1 descriptions of the nature of each defect may revea1 that a common genetic factor is responsible for the coexistence of both disorders. SUMMARY
A twenty-eight year old euthyroid Negro woman was studied for congenital deafness and goiter. The ability of her thyroid gland to accumulate radioiodine was normal. Dehalogenase activity was also normal, since monoiodotyrosine given orally was deiodinated at a normal rate. No abnormal iodoproteins were found in the thyroid gland, serum or urine. In contrast to AMERICAN
JOURNAL
OF
MEDICINE
Congenital
Deafness and Goiter-Hollander
previously described deaf patients with goiter, this subject was able to iodinate tyrosine. No thyroxine was found in a concentrated hydrolysate of thyroid tissue, although normal concentrations of thyroxine were present in serum. It is postulated that this patient has a partial defect in the condensation of iodotyrosines to form iodothyronines and that whatever thyroxine and triiodothyronine her gland did synthesize were rapidly released. Alternative hypotheses which cannot be excluded by the studies are considered. Seven other nondeaf goitrous subjects had reduced but measurable quantities of iodothyronines in their thyroid glands. Although the goitrous deaf subject had an intact vestibular apparatus, audiometric studies revealed total loss of hearing. Direct stimulation showed the absence of cochlear and eighth nerve action potentials. This suggests that the hearing loss is secondary to disease of the organ of Corti. Congenital deafness and goiter is a heritable disorder, but the precise relationship of one defect to the other is unknown. Acknowledgment: We wish to thank Drs. William M. Shelley and Theodore Winship for reviewing the histologic sections, Dr. Michael T. Harrison for helpful suggestions and Miss Janice Huth for technical assistance. REFERENCES
1. Cited by THOULD, A. K. and SCOWEN, E. F. The syndrome of congenital deafness and simple goitre. In: Advances in Thyroid Research, p. 22. Edited by Pitt-Rivers, R. London, 1961. Pergamon Press, Inc. 2. PENDRED, U. Deaf-mutism and goitre. Lancet, 2: 532, 1896. 3. STANBURY, J. B. Familial goiter. In: The Metabolic Basis of Inherited Disease. D. 273. Edited bv Stanbury, J. B., Wyngaarden, J. B. and Fredrickson, D. S. New York, 1960. McGraw-Hill Book Co., Inc. 4. MORGANS, M. E. and TROTTER, W. R. Association of congenital deafness with goitre. &ncet, 1: 607, 1958. 5. FRAZER, G. R., MORGANS, M. E. and TROTTER, IV. R. The syndrome of sporadic goitre and congenital d.eafness. Quart. J. Med., 29: 279, 1960. 6. RUBEN, R. J., BORDLEY, J. E. and LIEBERMAN, A. T. Cochlear potentials in man. Lar~ngosco~c, 71: 1141, 1961.
VOL.
37,
OCTOBER
1964
et al.
637
7. BLOCK, R. S., WERNER, S. C. and MANDL, K. Ill. 11 method for the investigation of the distrihntion of radioiodine in the serum after small test doses of I-131. drch. Biochem., 73: 9, 1958. 8. BIRD, R. and FARRAN, H. E. A. A sensitive method for the detection of iodinated compounds in human plasma and its applications in the study of thyrotoxicosis. J. Clin. Endocrinol., 20: Xl, 1360. 9. STANBURY, J. B., KASSENAAR, A. A. Ill., MEIJER, J. W. A. and TERPSTRA, J. The occurrence of mono- and diiodotyrosine in the blood of a patient with congenital goiter. J. Clin. Endomnol., 15: 1216, 1955. 10. BLOCK, R. J., DURRUM, E. I,. and ZW~IG, G. A Manual of Paper Chromatography and Paper Electrophorrsis. New York, 1955. Academic Press. Inc. 11. RUBEN, R. .I., LIEHERMAN,A. T. and BOKDI.EI., .I. E. Some observations of cochlear potentials and nerve action potentials in children. L~rvnq~cr$e, 72: 545, 1962. 12. FEDERMAN, D., ROBBINS, J. and RALL, J. E. Some observations on cretinism and its treatment. ,Vrze, En,
Deafness
and Goiter*
Studies of a Patient With a Cochlear Defect and Inadequate Formation of Iodothyronines CHARLES S. HOLLANDER, M.D.,~ THADDEUS E. PROUT, M.D., MACCALLUM RIENHOFF, M.D.,$ ROBERT
J.
RUBEN, M.D. t and SAMUEL P. ASPER, JR., M.D. Baltimore, Maryland
G
OITERassociated with deafness was recognized by Bueno [7] in 1769, Wood [I] in 1824 and Pendred [Z] in 1896 and is referred to as Pendred’s syndrome. The defect in the synthesis of thyroid hormone in goitrous deaf patients has been characterized as a failure of iodination of tyrosine [3-51. The nature of the hearing loss in these patients has not been extensively studied. This report consists of a study of a patient with goiter and deafness whose abnormality in formation of the thyroid hormones, in contrast to previously described patients, was due to a defect other than inadequate iodination of tyrosine and whose deafness, studied by recently improved procedures [6], was due to a defect in cochlear reception.
CASEREPORT The patient (A. M. J., No. 101 03 76) was a twentyeight year old Negro mother of six children. She was admitted to the Johns Hopkins Hospital for evaluation of goiter and deafness. The mother of the patient had a large goiter which was first noted at about twenty years of age. The patient has seven siblings of whom only two were available for examination. They were clinically euthyroid with normal hearing, but one of them, a thirty-five year old sister, had a diffuse uniform enlargement of the thyroid gland to about four times normal size. The only child of the patient’s first marriage was said to have normal hearing and a goiter, but neither this child nor her first husband was available for examination. Her second husband was deaf from birth but had no goiter. Two sons and one daughter of the second marriage are deaf; two other children of this marriage have normal hearing. A deaf male child and a female child with normal hearing were examined, and neither had a goiter.
The patient was born in North Carolina; she is congenitally deaf with associated mutism although she can enunciate a few words. She reached the eleventh grade at a state school for the deaf. At the age of twenty-six, two years prior to admission, the patient noted the onset of dysphagia. Simultaneously she became aware of an asymmetric enlargement of her neck, greater on the right side. She had no symptoms of hyperthyroidism or hypothyroidism. Six months prior to admission she complained of pain and tenderness in her neck for a period of several weeks. The pain subsided, and upon admission her only symptom was moderately severe dysphagia. The patient had not taken iodine, desiccated thyroid or any known goitrogen. Physical examination revealed an intelligent, cooperative woman of healthy appearance with normal temperature, blood pressure of 122/84 mm. Hg and pulse rate of 72 per minute. The respirations were regular at 16 per minute. She was deaf. The tympanic membranes appeared normal. Her thyroid gland was diffusely enlarged, the right lobe being approximately five times normal size and the left lobe twice normal size. No nodules were felt. There was no thrill or bruit over the gland. She had incurved fifth fingers bilaterally (clinodactyly). The skin, eyes, reflexes and remainder of the examination were within normal limits. Laboratory examinations revealed a hematocrit of 42 per cent and a hemoglobin of 12.4 gm. per 100 ml. The total white blood cell count was 5,250 per cu. mm. with 52 per cent polymorphonuclear leukocytes, 35 per cent lymphocytes, 4 per cent basophils, 3 per cent monocytes and 6 per cent eosinophils. Urinalysis was normal with a specific gravity of 1.013. The serum levels of urea nitrogen, fasting blood sugar, carbon dioxide-combining power, chloride, phosphorus, sodium and potassium were normal. The results of other tests were as follows: cephalin floccula-
* From The Departments of Medicine an-l Surgery, The Johns Hopkins University, Baltimore, Maryland. This study was supported in part by Grant A-2041 from the U.S. Public Health Service. Manuscript received September II, 1963. 7 Present address: National Institutes of Health, Bethesda, Maryland. $ Present address: Department of Pathology, University of Colorado Medical School, Denver, Colorado. 630
AMERICAN
JOURNAL
OF
MEDICINE
Congenital Deafness and Goiter-Hollander TABLE DISTRIBUTION
-
OF I’31
Comnonent Condition
Subject
Dose (PC.)
1 2 3 4 5 6 7 8 9 10*
Nongoitrous Nongoitrous Nontoxic goiter Nontoxic goiter Nontoxic goiter Colloid adenoma Colloid adenoma Colloid adenoma Colloid adenoma Congenital goiter and deafness
300 200 200 200 200 200 200 200 200 100
631
1
IN THE HUMAN THYROID
Time After I’31
1131
et al. GLAND
of Thvroid Hormone total radioactivity)
(% of
-
I Ratio of Monoiodotyrosine Diiodotyrosine
-
(hr.)
Monoiodotyrosine
Diiodotyrosine
Triiodothyronine
Thyroxine
45 48 24 48 48 24 48 48 72
32.6 25.1 29.3 49.5 33.4 34.8 38.0 28.7 31.9
47.3 58.6 63.6 34.5 59.6 60.0 50.5 60.3 55.4
0.5 ... 0 0 0 < 0.5 0 < 0.5 0
10.1 9.1 2.2 5.4 4.7 1.1 2.4 3.5 6.0
0.69 0.48 0.46 1.40 0.56 0.50 0.75 0.48 0.58
56
87.0
13.0
0
0
6.50
-
:
-
NOTE: Ten subjects, either healthy or with thyroid disorders as shown, were given radioiodine orally and later, at subto:al thyroidectomy, tissue was taken for analysis of radioiodine in various components of the thyroid hormones, thyroxine and triiodothyronine, and their precursors, monoiodotyrosine and diiodotyrosine. * Patient A. M. J.. tion 2+ at 48 hours, thymol turbidity 9.2 units, serum cholesterol 250 mg. per cent, serum proteins 6.7 gm. per cent of which 5.0 gm. was albumin and 1.7 gm. was globulin, serum bilirubin 0.8 mg. per cent, and alkaline phosphatase activity 3.0 Eodansky units. The retention of bromsulfalein was 3 per cent at 45 minutes. Hemoglobin was normal by electrophoresis, and the lupus erythematosus cell preparation and results of a serologic test for syphilis were negative. The mastoids were normal on roentgenogram. The chest roentgenogram and the scintiscan of the thyroid gland showed the upper portion of the trachea to be moderately displaced to the left by a markedly enlarged right lobe of the thyroid gland. The serum protein-bound iodine and the butanolextractable iodine were 6.0 and 4.6 pg. per cent, respectively. The radioiodine uptake by the thyroid gland was 41 per cent at 2 hours and 39 per cent at 24 hours. Other special studies of thyroid function are reported subsequently. Studies of vestibular function were normal. Chromosomal studies showed a normal idiogram consisting of 46 chromosomes. A subtotal thyroidectomy was performed. The entire right lobe, containing a large nodule, and most of the left lobe were removed. The excised tissue weighed 160 gm., and approximately 40 gm. of tissue was left in situ. The bulk of the tissue was used in special studies to be reported. Histologic sections of the nodule and surrounding tissue were examined. The nodule was composed of macrofollicles containing colloid; the tissue surrounding the nodule was hyperplastic. VOL..
37,
OCTOBER
1964
METHODS AND MATERIALS Several studies were conducted prior to subtotal thyroidectomy. Radioiodine (20 PC,) was administered orally to the patient, and the thyroidal uptake was measured at intervals. When the radioiodine reached a relative plateau in the thyroid gland, the patient was given 1.8 gm. potassium thiocyanate orally. On a second occasion 1.0 gm. of potassium perchlorate was employed. The emanations from the thyroid gland were measured by a Baird-Atomic@’ detector which activated an Esterline-Angus@ recorder. The detector was equipped with a collimator to minimize the background interference. Background readings were made without moving the patient by inserting a lead shield into a holder placed between the thyroid gland and the counter. Continuous counts were recorded for two hours after the administration of both potassium thiocyanate and potassium perchlorate. The purity of monoiodotyrosine,* labeled with Ii3i (approximately 3.22 PC. per mg.), was demonstrated chromatographically. An amount containing 50 PC. of Ii3’ was administered orally to the patient and to one normal subject. Fractional urine collections were obtained 2, 4, 6 and 24 hours thereafter. Serum was obtained from the goitrous subject at 48 hours. The protein-bound I*ri was then determined by two methods. In the first, 5 ml. of serum was subjected to trichloracetic (5 per cent) precipitation, and the amount of radioactivity remaining with the washed * Abbott Laboratories,
North Chicago,
Illinois.
Congenital Deafness and Goiter-Hollander
632
IBgm.
et al.
KSCN
+
Q-_-Q--*
_,__Q___Q--
---___
KSCN
___________________~
,..-a ,/& __&__------+-*-_____ .‘a
,* ,/’
‘““P
Kc’o4 0
-C-s-------
*------____
------_______*
y’
KC104
IO’
,d (// t__~_,____________________-_-___-----------------------.’
: 8’
’
i
_____---x---
------_
__-_____-__--__-x________I
;
Control
I
,’ I’
:
,1
/’
: :
,I’
,’
,’
: +
TEST
I- 131
/’ I’
:
_--
_.*-
:
:
I I( ! ’ I’
5 UC
x-----x
Control
20 UC
o-----o
KSCN
l.Swn.
24~
e-----e
KC104
I.Ogm.
I
:: If
30
m
90
120
150
130
210
*4PGz
TIME IN MINUTES FIG. 1. Patient A. M. J. with congenital deafness and goiter. The radioiodine content, recorded as counts per minute, of the thyroid gland during three separate 24-hour tests. Neither potassium perchlorate (KCIOI) nor potassium thiocyanate (KSCN) caused release of radioiodine from the gland. This indicates that the gland of this patient was able to iodinate tyrosine. Radioiodine was given orally at time zero. precipitate was measured. In the second, 5 ml. of serum was passed through an anion exchange resin to adsorb free iodine (Amberlite IRA 400@) and the residual amount of radioactivity determined. T’he thyroid glands of the goitrous deaf patient, seven patients with goiter and two normal subjects were removed. All had received doses of Ir3r varying from 100 to 300 PC. 24 to 72 hours before surgery. (Table I.) Extracts of thyroid [7], serum [8] and urine [9] were concentrated in a flash evaporator and subjected to descending chromatography on filter paper. In all instances, standard solutions of monoiodotyrosine, diiodotyrosine, iodine, L-thyroxine and triiodothyronine were used as markers. The solvent systems used were: n-butanol-acetic acid (2N)-water (450: 50: 125 v/v), n-butanol saturated with 2N ammonium hydroxide, n-butanol-dioxane-ammonia (2N) (80: 20: 100 v/v) and tertiary amyl alcohol saturated with 2N ammonium hydroxide [ 701. Chromatography was performed in duplicate on
each sample. One of the chromatograms was stained with a solution of ceric sulfate-arsenious acid [a]. The other chromatogram was dried, cut into 0.5 cm. strips, placed in plastic test tubes and the amount of radioactivity measured in a Baird-Atomic well-type scintillation counter. Studies of the labyrinth were carried out in the deaf patient four weeks after thyroidectomy. The vestibular apparatus was tested by means of Barany chair rotation and cold caloric stimulation. Hearing studies were carried out with routine pure tone audiometry, bone conduction, speech discrimination and psychogalvanic skin resistance. Following the routine studies, direct measurements of cochlear function were made. Details of this procedure have been published previously [6,77]. Under general anesthesia, the tympanic membrane was reflected and a small electrode was placed in the round window niche. The round window responses were amplified and recorded while the ear was being stimulated by pure tones and clicks. The maximum AMERICAN
JOURNAL
OF
MEDICINE
Congenital
Deafness
and Goiter--H&m&r
et ul.
633
Iodide It--H Total Counts:3,763
mo
600 0) 2 izi500 ti CL I.0 E2 400 u '; z 300
200 MIT 1-1
DIT Ic---*l
$&
100 < 7c
Centimeters
FIG. 2. Patient ‘4. M. J. with congenital deafness and goiter. Graphic representation of data obtained by paper chromatography of urine collected from the sixth through the twenty-fourth hour following administration of monoiodotyrosine Ii3r. The radioactivity excreted was entirely iodide. This indicates a normal mechanism for deiodination of tyrosine. Keference positions for monoiodotyrosine (MIT), diiodotyrosine (DIT), triiodothyronine (Ta) and thyroxine (T~J in this solvent system are shown. intensity decibels.
used
for
pure
tone
stimulation
was
100
RESULTS
‘l’he goitrous deaf patient was given radioiodine to determine whether the gland had normal mechanisms for concentrating iodine (“trapping”) and for iodinating tyrosine (“organification”) [3]. Evidence that the gland was able to concentrate iodide was obtained by demonstration that 41, 40 and 39 per cent of the administered Ii3i was taken up by the gland at 2, 4 and 24 hours, respectively. On separate occasions the patient was given radioiodine followed by potassium thiocyanate or potassium perchlorate as shown in Figure 1. The thyroid gland failed to release the Ir3i on both occasions. Radioiodine which had not been converted to the tyrosyl constituents of the gland would have been discharged from the gland by these agents. VOL.
37,
OCTOBER
1964
Monoiodotyrosine-Ii3i was administered orally to the patient and to one normal subject. Fractional urine specimens were collected from each subject at 2, 4, 6 and 24 hours. Chromatography of the urine extracts, performed in three solvent systems, revealed that Ii31 was excreted in both subjects. These results establish that the patient (Fig. 2) has a normal ability to deiodinate monoiodotyrosine. The patient was given 100 PC. of InSi, and serum samples were collected at 24 and 48 hours and at the time of subtotal thyroidectomy (56 hours). In all three samples, at least 94 per cent of the amount of radioactivity contained in the serum was butanolextractable. The concentrated butanol extract was chromatographed in butanol-ammonia and tertiary amyl alcohol-ammonia solvent systems. In butanolammonia solvent, 90 per cent of the amount of radioactivity migrated to the area of thyroxine and approximately 10 per cent to that of triiodothyronine. No radioactivity was detectable in the areas of diiodo-
634
Congenital
1
Deafness and Goiter--HoZZunder et al.
24
Total Countsl20;175
Totai Counts:1,665
Centimeters FIG. 3. Patient A. M. J. with congenital deafness and goiter. Graphic representation of data obtained by paper chromatography of serum obtained 24 hours after administration of radioiodine is shown. The radioactivity present was found to be in thyroxine or triiodothyronine. No other iodinated compounds were found. Explanation of abbreviations is given in Figure 2.
tyrosine or monoiodotyrosine. (Fig. 3.) In the tertiary amyl alcohol-ammonia system a better separation of thyroxine and triiodothyronine was achieved, and 97 per cent of the amount of radioactivity was localized to the area of thyroxine. Saline extracts of the butanol-insoluble fraction of the serum were also chromatographed in these solvent systems; the radioactivity of this material was not localized to any specific area. The protein-bound 1”’ was determined by two different methods upon 5 ml. of the serum collected at 48 hours. In both instances a high normal value of 0.4 per cent was obtained. The bulk of the gland obtained at operation was subjected to tryptic digestion. Butanol extracts of the hydrolysate were concentrated and chromatographed in two solvent systems. The amounts of monoiodotyrosine and diiodotyrosine found indicated that adequate digestion of the gland had been obtained. No thyroxine or triiodothyronine was present in the concentrate obtained from 100 gm. of thyroid gland. Although the ratio of monoiodotyrosine to diiodotyrosine varied in the different solvent systems, the differences were slight, and the ratio was approximately 6.5 to 1. (Fig. 4.) The distribution of radioactivity in the thyroid
gland of this patient is shown in Table I with results of similar studies in other subjects. In nontoxic goiter and in colloid adenomas the amounts of thyroxine-P in the gland at 48 hours ranged from 2.4 to 5.4 per cent; whereas none was found in the patient. The vestibular studies revealed normal function. All of the audiometric studies revealed a total hearing loss. Occasionally, there would be some response at 1,000 cycles with an 85 decibels sound intensity; this response, however, was not consistent and probably represents tactile appreciation. The middle ear was normal. Recordings at the round window niche revealed total absence of cochlear potentials and eighth nerve action potentials. COMMENTS
A specific defect in the synthesis of thyroxine has been defined in five types of familial goiter. First, goiter may be caused by inability of the thyroid gland to trap iodide [ 72,731. Secondly, goiter may also be produced if the thyroid gland is unable to convert inorganic iodide into an organic form [74,75]. This latter defect in thyroxine synthesis can be recognized by the AMERICAN
JOURNAL
OF
MEDIOINE
Congenital Deafness and Goiter--H&n&r
et al.
635
Iodide
Centimeters
FIG. 4. Patient A. M. .I. with congenital deafness and goiter. Graphic representation of data obtained on paper chromatography of an extract of the thyroid gland obtained 56 hours after oral administration of In1. A portion of the extract that was presumabIy not completely enzymatically digested remained at origin as shown. The ratio of total units of monoiodotyrosine In1 to diiodo6.5 to 1. No measurable amounts of either tyrosine I13i was approximately thvroxine I’si or triiodothvronine Ii3’ were found. Explanation of abbreviations ,is given in Figure 2.
characteristic release of labeled iodine from the thyroid gland when either perchlorate or thiocyanate is administered. A similar and closely related type exists in deaf patients with a less severe defect in iodination of tyrosine [4,5]. The deafness in these patients is also familial. Although it was presumed initially that the patient had this type of defect, the studies revealed that her gland did not contain significant amounts of free I13’. It was concluded that she did not have a defect in the ability either to accumulate iodine or to iodinate tyrosine. Two other metabolic defects causing familial sporadic goiter are impaired dehalogenase activity [76] and the synthesis of abnormal iodoproteins [77]. Since all of the monoiodotyrosine-Ill3 administered to this patient was ex“01..
37,
OCTOBER
1964
creted as free iodide, it was concluded that dehalogenase activity was normal. In the butanol extract of the serum following administration of 113’ to the patient, over 90 per cent of the amount of radioactivity was in thyroxine, and the remainder was in triiodothyronine; no monoiodotyrosine, diiodotyrosine or abnormal iodinated thyroid proteins were detected. Moreover, 94 per cent of the amount of radioactivity in the serum was butanol-extractable, and no abnormal iodoprotein could be detected upon chromatography of saline extracts of the butanolinsoluble fraction of the serum. The fifth and remaining defect of thyroxine synthesis to be considered is an impaired condensation of iodotyrosines to produce iodothyronines [78]. The goitrous deaf patient of this study was given 100 PC. of 1131 56 hours prior to
636
Congenital Deafness and Goiter-Hollander
subtotal thyroidectomy. Following surgery the excised portion of the gland was subjected to tryptic hydrolysis, extraction, concentration and chromatography. Monoiodotyrosine and diiodotyrosine were present in a ratio of 6.5 to 1, and no thyroxine or triiodothyronine was detectable. This patient was the only one among the ten subjects (two normal and eight goitrous) studied who had no iodothyronines in the thyroid gland. In patients with nontoxic goiter or with colloid adenoma the amount of thyroxine in the thyroid gland was less than that found in two normal subjects. Others have found the level of the iodothyronines to be low in patients with colloid goiter [79,20]. In this study the ratios of monoiodotyrosine to diiodotyrosine in the patients with nontoxic goiter and colloid adenoma were similar to those found in the normal subjects. The absence of iodothyronines in our patient is not simply a result of slow formation of triiodothyronine and thyroxine from a sluggish, colloid filled gland. Adequate time was allowed for the synthesis of iodothyronines as shown by the ability of other patients with colloid goiter to synthesize reduced but readily measurable quantities of iodothironines within 48 hours. Moreover, the high normal protein-bound 1131 value indicated that there is a small pool of 1131 within the gland turning over rapidly to permit the achievement of a eumetabolic state. On the basis of these observations it is postulated that our patient has a partial defect in the condensation of iodotyrosines. It is not possible to define this defect by a single simple laboratory test, The diagnosis is based on the chromatographic analysis of the labeled materials in the thyroid gland following oral administration of I 131. In such persons labeled iodotyrosines are found in great abundance, and labeled iodothyronines are absent. The prevailing hypothesis to account for these findings is the absence of a factor necessary for formation of the ether linkage of the thyronines. Although an enzymatically controlled process of condensation has been postulated, no enzyme capable of catalyzing this reaction has been demonstrated in mammalian thyroid tissue. Alternative hypotheses include the following: (1) steric interference with approximation of the tyrosyl constituents; (2) competitive inhibition of condensation by abnormal tyrosyl derivatives; and (3) defective formation of diiodotyrosines, as shown by the high ratio of monoiodotyrosine to
et al.
diiodotyrosine with consequent impedance of thyroxine formation. Available technics do not permit differentiation among these alternatives. Whatever the mechanism for the failure of thyroxine synthesis, the severity of the defect may vary from one patient to another. For example, of five patients recently described, three were hypothyroid and retarded [21,22], whereas two others were euthyroid [78]. The goitrous deaf patient in the present study also was euthyroid and had normal levels of thyroxine and butanol-extractable iodine in the blood. Since no thyroxine was found in her gland and an adequate quantity was present in serum, it appears likely that the thyroxine formed despite the partial defect was rapidly released from the gland. The patient had normal vestibular response but no hearing. The absence of the cochlear potential and the eighth nerve action potential indicates that the hearing loss is secondary to disease of the organ of Corti, probably related to the lack of hair cells. The patient then has a normal vestibular apparatus, crista, utricle and possibly saccule, and a diseased cochlea. The relationship of the patient’s thyroid defect to her deafness is uncertain. Specific cochlear deafness, first described by Siebenmann, according to Batsakis and Nishiyama [23], was noted in association with endemic goiter in the Swiss Alps. Section of the temporal bones at autopsy of these patients revealed degeneration of the organ of Corti and of the macula of the saccule. The crista of the semicircular canals and the macula of the utricle were found to be intact. The patient described herein has a definite cochlear lesion; whether this is the exact lesion described by Siebenmann cannot be determined. Study of other patients with goiter and deafness with carefu1 descriptions of the nature of each defect may revea1 that a common genetic factor is responsible for the coexistence of both disorders. SUMMARY
A twenty-eight year old euthyroid Negro woman was studied for congenital deafness and goiter. The ability of her thyroid gland to accumulate radioiodine was normal. Dehalogenase activity was also normal, since monoiodotyrosine given orally was deiodinated at a normal rate. No abnormal iodoproteins were found in the thyroid gland, serum or urine. In contrast to AMERICAN
JOURNAL
OF
MEDICINE
Congenital
Deafness and Goiter-Hollander
previously described deaf patients with goiter, this subject was able to iodinate tyrosine. No thyroxine was found in a concentrated hydrolysate of thyroid tissue, although normal concentrations of thyroxine were present in serum. It is postulated that this patient has a partial defect in the condensation of iodotyrosines to form iodothyronines and that whatever thyroxine and triiodothyronine her gland did synthesize were rapidly released. Alternative hypotheses which cannot be excluded by the studies are considered. Seven other nondeaf goitrous subjects had reduced but measurable quantities of iodothyronines in their thyroid glands. Although the goitrous deaf subject had an intact vestibular apparatus, audiometric studies revealed total loss of hearing. Direct stimulation showed the absence of cochlear and eighth nerve action potentials. This suggests that the hearing loss is secondary to disease of the organ of Corti. Congenital deafness and goiter is a heritable disorder, but the precise relationship of one defect to the other is unknown. Acknowledgment: We wish to thank Drs. William M. Shelley and Theodore Winship for reviewing the histologic sections, Dr. Michael T. Harrison for helpful suggestions and Miss Janice Huth for technical assistance. REFERENCES
1. Cited by THOULD, A. K. and SCOWEN, E. F. The syndrome of congenital deafness and simple goitre. In: Advances in Thyroid Research, p. 22. Edited by Pitt-Rivers, R. London, 1961. Pergamon Press, Inc. 2. PENDRED, U. Deaf-mutism and goitre. Lancet, 2: 532, 1896. 3. STANBURY, J. B. Familial goiter. In: The Metabolic Basis of Inherited Disease. D. 273. Edited bv Stanbury, J. B., Wyngaarden, J. B. and Fredrickson, D. S. New York, 1960. McGraw-Hill Book Co., Inc. 4. MORGANS, M. E. and TROTTER, W. R. Association of congenital deafness with goitre. &ncet, 1: 607, 1958. 5. FRAZER, G. R., MORGANS, M. E. and TROTTER, IV. R. The syndrome of sporadic goitre and congenital d.eafness. Quart. J. Med., 29: 279, 1960. 6. RUBEN, R. J., BORDLEY, J. E. and LIEBERMAN, A. T. Cochlear potentials in man. Lar~ngosco~c, 71: 1141, 1961.
VOL.
37,
OCTOBER
1964
et al.
637
7. BLOCK, R. S., WERNER, S. C. and MANDL, K. Ill. 11 method for the investigation of the distrihntion of radioiodine in the serum after small test doses of I-131. drch. Biochem., 73: 9, 1958. 8. BIRD, R. and FARRAN, H. E. A. A sensitive method for the detection of iodinated compounds in human plasma and its applications in the study of thyrotoxicosis. J. Clin. Endocrinol., 20: Xl, 1360. 9. STANBURY, J. B., KASSENAAR, A. A. Ill., MEIJER, J. W. A. and TERPSTRA, J. The occurrence of mono- and diiodotyrosine in the blood of a patient with congenital goiter. J. Clin. Endomnol., 15: 1216, 1955. 10. BLOCK, R. J., DURRUM, E. I,. and ZW~IG, G. A Manual of Paper Chromatography and Paper Electrophorrsis. New York, 1955. Academic Press. Inc. 11. RUBEN, R. .I., LIEHERMAN,A. T. and BOKDI.EI., .I. E. Some observations of cochlear potentials and nerve action potentials in children. L~rvnq~cr$e, 72: 545, 1962. 12. FEDERMAN, D., ROBBINS, J. and RALL, J. E. Some observations on cretinism and its treatment. ,Vrze, En,