Carrier detection in ornithine transcarbamylase deficiency

Volume 93 Number I

Brief clinical and laboratory observations

course. Association of HLA-B7 with SSPE has also been reported. One o f o u r patients, E. K., is HLA-B7 as are the two other patients with this syndrome whose HLA types are known to us. The association of hypogammaglobttlinemia with IILA-B7 and/or -DW2 might predispose a patient to this syndrome. Although we recognize that B7 is a common allele, it may be possible to identify the patients at risk. This syndrome also indicates that specific antibody at the site of infection is probab!y necessary to control certain viral infections of the central nervous system, especially those from enteroviruses. Attempts at therapeutic intervention have not been successful. The use of specific hyperimmune globulin to the suspected viral 9agent and immunostimulants have likewise been unsuccessfu! in arresting the progressive deterioration of the patient's mental and physical status'- " when initiated late in the disease. Agaressive therapy with anti-viral agents might be i effective if initiated early i n the course of recurrent aseptic meningoencephalitis in patients with hypogammaglobulinemia. We thank Drs. G. Geraldo and C. Wilfert fo~ special viral studies, Dr. L. Myers for measles specific LIF assays, and Doctors R. Seeger and R. Stevens for in vitro antibody production studies in our patient. REFERENCES

75

2. ttong R, Santosham M, Schulte-Wissermann H, Horowitz S, Hsu SH, and Winkelstein JA: Reconstitution of B and T lymphocyte function in severe combined immunodeficiency disease after transplantation with thymic epithelium, Lancet 2:1270, 1976. 3. Medical Research Council Working Party: Hypogammaglobulinemia in the United Kingdom, Medical Research Council Special Report No. 310, London, 1971. 4. Hanissian AS, Jabbour JT, Lamereus S, Garcia HJ, and ttorta-Barbosa L: Subacute encephalitis and hypogammaglobulinemia, Am J Dis Child 123:151, 1972. 5. White HH, Kepes JH, Kirkpatrick Ctl, and Schimke RN: Subacute encephalitis and congenital hypogammaglobulinemia, Arch Neurol 26:359, 1972. 6. LyonG, GriscelliC, and Lebon P: Endothelial intracisternal tubular inclusions in a case of chronic encephalitis associated with immunological deficiency, Neur0padiatrie 3:459, 1972. 7. Lord RA, Goldblum RM, Forman PM, Duprees E, Storey WD, and Goldman AS: Cercbrospinal fluid in lgM in the 9qbsence of serum IgM in combined immunodeficiency, Lancet 2:528, 1973. 8. WebsterADB, and Good RA: Primary immunodeficiency, Prog Immunol 11, 5:361, 1974. 9. Whisnant JK, Treadwell EL, Mohanakumar T, Wilfert CM, and Buckley RII: Prolonged CNS viral infection with ECtlO 30 in an agammaglobulinemia child with intact cell: mediated immunity, Pediatr Res 9:336, 1975. 10. BardelasJA, Winkelstein JA, Seto DS, Tsai T, and Rogor AD: Fatal ECtlO 24 infection in a patient with hypogammaglobulinemia: Relationship to dermatomhositis-like syndrome, J PEt)tATR90:396, 1977.

1. Barnett EV, Winkelstein and A, Weinberger tlJ: Agammaglobulinemia with polya(thritis and subcutaneous nodules, Am J Med 48:40, 1970.

Carrier detection in ornithine transcarbamylase deficiency Jerold T. llokanson, IM.D., William E. O'Brien, Ph.D., Judi Idemoto, M.S.S.A, and Irwin A. Schafcr, M.D.,* Cleveland, Ohio

ORINTItlNE

TRANSCARBAMYLASE

DEFICIENCY

is

an X-linked recessive disorder which usually causes lethal hyperammonemia.'--" Carrier females show variable From the Case IVestern Reserre Universit), Department of Pediatrics, Division of Human Genetics, Cleveland Metropolitan General Hospital. Supportedfrom Grantsfrom The Cleveland Foundation and The National Foundation-March of Dhnes. Presented at Tire Societ)'for Pediatric Research St. Louis, April 1976. *Reprint address: Cleveland Metropolitan General Hospital. 3395 Scranton Road, Cleveland, 011 44109.

0022-3476/78/0193-0075500.40/0 9 1978 The C. V. Mosby Co.

degrees of protein intolerance depending on the proportion of functionally active X chromosomes that carry the mutant gene. Carrier detection by measurement of enzyme activity requires percutaneous liver or intestinal Abbreviation used OTC: orinthine transcarbamylase biopsies, since the enzyme is not present in cultured fibroblasts or white blood cells. Until recently, noninvasive methods of carrier detection were limited to biood ammonia determination following anamonium chloride or protein loading? The observation that patients with 0 T C

76

Brief clinical and laboratory observations

TI,e Journal of Pediatrics Jul)' 1978

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Fig. i. Family pedigree.

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following oral protein loads. We report the results of protein-loading studies in another large kindred with OTC deficiency, which confirm the findings of Goldstein and suggest that orotic aciduria may be a more sensitive marker for carrier detection compared to the measurement of ammonia alone.

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Fig. 2. The effect of protein loading on the excretion of orotic acid in the urine. The data from seven normal adults are expressed as the mean (solid line) • 1 SD (stipled area). All patients tested received I gm protein/kg body weight. deficiency excrete increased amounts of orotic acid, uridine, and uracil in the urine suggested another method to monitor ammonia metabolism.' Goldstein et aP first presented evidence that obligate OTC deficiency carriers excrete increased concentrations of orotic acid in the urine

AND METHODS

The pedigree of the affected family is depicted in Fig. I. The proband, a female (IV-9), became comatose following an upper respiratory infection with an elevated blood ammonia level o f 350 #g/dl and urinary orotic acid excretions of up to 3,924/ag/mg creatinine. She died after eight days on a respirator. Studies of urea cycle enzymes in a postmortem liver specimen showed OTC activity which was 8 to 15% of control values. The activity of other urea cycle enzymes was normal. The diagnosis of OTC deficiency, was confirmed in this family following the birth of a male first cousin (IV-24) who at 24 hours of age became irritable, fed poorly, and developed a chaotic movement disorder suggesting asterixis. Over the next 30 hours he became increasingly lethargic, tachypneic, and the blood ammonia concentration rose to 1,956 pg/dl. He died at 61 hours of age. Virtually no OTC was detected in liver post mortem. The other urea cycle enzyme values were normal except for that of argininosuccinate synthetase which was also low. The pedigree shows a number of unexplained male deaths in generations II and IV. Based on the enzyme,

Volume 93 Number 1

clinical, and pedigree data, the mothers (111-3, I11-10) of the two infants who died, and the maternal grandmother (II-4) were designated obligate heterozygotes. The maternal grandmother had no symptoms but the other two women frequently developed nausea, dizziness, and headaches following meat ingestion and voluntarily restricted meat intake. Oral protein loads (I gm/kg) in the form ofsteak, milk, and eggs were given to the three obligate heterozygotes. Other females tested were II1-5, II1-7, III-8, and all living daughters of III-3, 1II-5, and III-10. The two males tested were IV-4 and IV-8. Six normal adults served as controls. Timed blood and urine specimens were collected following the protocol of Goldstein? Urine orotic acid levels were measured by a modification of the method of Stajner et al ~ and plasma ammonia concentrations by the spectroph0tometric method of Mondzae et al.' Assays for urea cycle enzymes were carried out by Dr. Phillip Snodgrass I VA Hospital, Indianapolis, Indiana by methods published from his laboratory? RESULTS Following the protein load the six adult controls showed normalconcentrations of plasma ammonia with little variation over the six-hour sampling period. The three obligate heterozygotes showed elevations of plasma ammonia levels which rose more than 3 SD from the mean of the controls three hours after the protein challenge (82, 149, 92 vs. 50.4- 8 ~g/dl). A significantly elevated value, 78 #g/dl, was observed in a child (IV-5) at three hours..The remaining females ranging in age from 3 to 32 years and two males, ages 10 and 17 years, did not vary by more than I SD from the mean of adult controls and were considered normal. Orotic acid excretion of the three obligate heterozygotes and one female offspring (IV-20) compared to the mean of seven normal adult controls is shown in Fig. 2. All rose by more than 3 SD above the mean of the controls. Interestingly, we did not detect abnormal plasma ammonia levels in the daughter (IV-20). All other family members had concentrations of orotic acid that were within 1 SD of the control subjects. To eliminate a potential error in expressing orotie acid excretion on the basis of urine creatinine, we also calculated total orotic acid excretion during the six-hour period of controlled protein intake. All'three obligate heterozygotes and the daughter (IV-20) excreted quantities oforotic acid 3 SD or more above the mean of the controls (9.67, 18.3, 34.0, 7.13 vs. 2.25_-. 1.16 mg/6 hours). These four individuals were excreting abnormal amounts of orotic acid as a consequence of protein ingestion. The total orotic acid excretion of all other family members fell within 1 SD of the control group.

Brief cfinical and laboratory observations

77

DISCUSSION The mechanism proposed for ammonia-induced orotic aciduria is based on the fact that carbamyl phosphate is one of the initial reactants for de novo pyrimidine synthesis. When cellular levels of ammonia become elevated carbamyl phosphate is synthesized by carbamyl phosphate synthetase I in the mitochondria at a rate faster than it can be utilized in the urea cycle. The excess carbamyl phosphate exits the mitochondria into the cytoplasm and is utilized for pyrimidine synthesis with resultant orotic aciduria. 9 Protein loading stresses this system and in heterozygotes with decreased OTC activity, orotic aciduria may occur in the absence of detectable hyperammonemia. Of the five obligate heterozygotes studied by Goldstein et aP or us, all showed orotic aciduria after protein loading while only four showed hyperammonemia. In addition, 15 possible carders have been studied in both kindreds. Four females, all of whom were daughters of obligate heterozygotes, showed orotic aciduria. Three of these possible carriers showed orotie aciduria without detectable hyperammonemia. Only one female was found who showed hyperammonemia without or0tic aciduria. The number of obligate heterozygotes that has been studied for orotic aciduria following protein loading is too small to evaluate the sensitivity of this method of carder detection. As with other X-linked traits, carders with near normal levels of OTC activity may not be detected by tissue enzyme measurements or by loading tests. The data collected thus far indicate that orotic aciduria following protein loading is an indicator of abnormal ammonia metabolism and should be evaluated further as a noninvasive method of carrier detection.

REFERENCES

1. Campbell AGM, Rosenberg LE, Snodgrass PJ, et ah Orithine transcarbamylase deficiency: A cause of lethal hyperammonemia in males, N Engl J Med 288:1, 1973. 2. Short EM, Conn HO, Snodgrass PH, et ah Evidence for X-linked dominant inheritance of ornithine transcarbamylase deficiency, N Engl J Med 288:7, 1973. 3. Hsia YE: Inherited hyperammonemic syndromes, Gastroenterology 67:347, 1974. 4. Levin B, Oberholzer VG, and Sinclair L: Biochemical investigations of hyperammonemia, Lancet 2:170, 1969. 5. Goldstein AS, ttoogenraad NH, Johnson JD, et al: Metabolic and genetic studies of a family with ornithine transcarbamylase deficiency, Pediatr Res 8:5, 1975. 6. Stajner A, Suva J, and Musil F: The determination oforotie acid in the blood serum by means of the spectrophotometric method, Experentia 24:116, 1968. 7. Mondzac A, Ehrlich GE, and Seegmiller JE: An enzymatic determination of ammonia in biological fluids, J Lab Clin Med 66:526, 1965. 8. Natale PJ, and Tremblay GC: Studies on the availability of

78

B r i e f clinical and laboratory observations

intramitochondrial carbamylphosphate for utilization in extramitochondrial reactions in rat liver, Arch Biochem Biophys 162:357, 1974.

The Journal o f Pediatrics Jul)' 1978

9. Nuzum CT, and Snodgrass PJ: Urea cycle enzyme adaptation to dietary protein in primates, Science 172:1402, 1971.

Renal carbuncle in a neonate with congenital nephrotic syndrome D. Beatty Crawford, M.B., F.R.C.R.,* Madjid Rasoulpour, M.D., Vijay M. Dhawan, 1M.D., George T. Klauber, M.B., F.R.C.S.(C), Ilelen K. Little, 5I.B., F.R.C.R., and Robert II. McLean, 51.D., Farmington, Conn.

R E N A L C A R B U N C L E S or abscesses are u n c o m m o n in

adults and rare in children.'. -" We believe this is the first report of this disorder in a newborn infant. The presence of congenital nephrotic syndrome (Finnish Type) predisposed 'this infant to infection and was presumably important to the development of the carbuncle. CASE REPORT A 2.i kg, 3-day-old infant, was transferred to John Dempsey Hospital, the University of Connecticut Health Center, with edema and proteinuria. The child was the product of a 36 weeks' gestation. Pregnancy and delivery were uncomplicated. Family history revealed no consanguinous marriages. The mother is of Finnish-P01ish ancestry and the father of Hungarian-Irish-Scottish origin. A sister, the first born sibling, died at 6 weeks of age from Escherichia coil septicemia. She had edema, proteinuria, and hypoproteinemia which developed shortly after birth. Postmortem examination revealed microcystie dilation of the proximal tubules compatible with findings seen in the Finnish-type congenital nephrotic syndrome." ~ The second and surviving sibling, a 3~A-year-old boy, has diabetes mellitus. Physical examination revealed mild generalized edema. Both kidneys were easily palpable, the left being slightly larger than the right. Blood urea nitrogen was 15 mg/dl and serum creatinine was 0.6 mg/dl. The serum sodium concentration was 147 mEq/I, potassium 4.8 mEq/l, chloride 100 mEq/l, and CO~ content 18 mEq/I. Total serum portein was 3.0 gm/dl and serum albumin concentration was 0.6 gm/dl. Urinalysis showed 4+ proteinuria and 15 to 20 red blood cells/high-powered field. The quantitative urinary protein was 1,050 mg/dl. VDRL was nonreactive. On the eighteenth day of life, the infant developed low-grade fever and vomiting. The left kidney was firm and larger than the right. Blood, urine, and spinal fluid cultures were obtained and the patient was treated with gentamicin and ampicillin. All

From the Unirersio" o f Connecticut ttealth Center. *Reprint address: Universityof Conneetieta Ilealth Center, Farmb~gton. CT 06032.

cultures were negative except that of urine, which produced E. coli > 100,000 col/ml. The intravenous urogram was abnormal; a crescent sign was noted during the nephrogram phase on the left side indicating a thin rim of renal parenchyma surrounding a large cavity. Later films demonstrated minimal excretion into a lower pole calyx. The right kidney was normal. Ultrasonography using a standard gray-scale machine with a 3.5 mtlz short-focal range transducer demonstrated a normal right kidney. On the left side, no normal renal tissue was seen but an extensive sonolucent mass was present. A few internal echoes were present and the outline of the sonolucent mass was slightly irregular (Fig. 1). A renal dynamic study following the intravenous administration of 1.0 mCi of .... Tc diethylenetriamine pentaacetic acid revealed absent perfusion in the upper two-thirds of the left kidney. Perfusion to the right kidney was normal. One-minute static blood pool image showed a rim of activity around the left kidney. Later views again demonstrated evidence of a thin rim of functioning tissue surrounding a large, avascular, spaceoccupying lesion. There was a small area of functioning tissue in the region of the lower pole. There was good concentration and clearance of radiotracer by the right kidney. The most likely diagnosis was a hydronephrosis involving the upper pole of a duplex left kidney. A percutaneous antegrade p)'elogram was therefore attempted. A 22-gauge, 3-inch spinal needle was inserted into the cystlike mass under ultrasonic guidance. ~~ On aspiration, 15 ml of thick purulent fluid was obtained. A small quantity of contrast medium was introduced; this demonstrated a large cavity involving most of the kidney. There was no evidence of communication with a collecting system. Pus culture grew E. coil Cell block for malignant cells was negative. Emergency nephrostomy was performed. Ten days later, a nephrostogram using Renografin 60 diluted with an equal volume of sterile water again demonstrated a large irregular cavil)', but contrast material was seen to enter the lower pole collecting system and pass down the ureter into the bladder (Fig. 2). One month later, a repeat intravenous urogram demonstrated

0022-3476/78/0193-0078500.30/0 9 1978 The C. V. Mosby Co.