The XYY syndrome

Review The XYY C:IIARI.ES

E.

M.D., JOHN

PARKER,

Syndrome*

MELNYK,

Los Angeles,

PH.D.

and CHARLES

H.

FISH,

x1.1).

California

The XYY syndrome is of particular interest since the extra Y chromosome 3eems to be related to personality traits and criminal behavior. A new case of XY\I syndrome is presented and discussed with relation to the present knowledge of rhe syndrome. Extensive laboratory data are presented, but no diagnostic abnormalities were found. Typical karyotypes, both meiotic and mitotic, are shown. nleiotic studies indicate that the extra Y chromosome is not transmitted to the progeny. Personality type and height remain the most outstanding features of the syndrome. There appear to be no diagnostic dermatoglyphic or histologic patterns. Althou,&., one can suspect the syndrome clinically, a karyotype is necessary IO prove the diagnosis.

T

lies

HE

manifestations

MAJOK

somal

abnormalities

usually

associated

.\ new

syndrome

chromosome

has

of most are

with

mental

associated been

physical with

children. ‘1‘1~~ mother had one miscarriage. He was born at home with normal labor and delivery. The father is a truck driver who had completed onme year of high school education. The mother received a high school diploma and all the siblings completed high school or better. They appear to be kind, gentle people. There is no family history of difficulty with the law or of aggressive behavior. The physical ,examination (Fig. 1) revealed a tall powerful-appearing man who was somewhat obese. He weighed 236 pounds, his arm spread was 83 inches, sitting_height 40 inches and standing height 7.5% inches. 1 he family members are relatively tall, yet the propositus stands out well above the others (Fig. 2). He has never married and has no children. He is a pleasant, cooperative man but has a history of temper outbursts. He works in the hospital laundry and on occasion has been restricted for striking at his various supervisors. His IQ score on the Stanford-Binet Intelligence Scale is 38. On examination the head was normocephalic with a low hairline over the forehead. The ears were normal in size, configuration and position. The eyes were normal and the face was somewhat distorted by a large, protruding mandible. His beard wa$ sparse and his teeth were in good condition. The lnn,ys were clear and the heart was nor-

chromoanoma-

retardation. an

extra

Y

reported

in which patients ha\-e distinguishing physical characteristics and aggressive behavior. Described herein is a new patient with this syndrome who has been studied extensively by cytogenetic and biochemical means. .4 review of the literature ant1 a discussion concerning the significance of this new synclrome are also included. PATIENT

SELECTION

It Fairview State Hospital in Costa Mesa, California, ten subjects were surveyed. The subjects were selected on the basis of hei@ (over 6 feet) and a history of aggressive behavior. One person was found to have the XYY constitution and another to have the XXYY constitution. CASF REPORT .I thirt)-eight year old white man was found to have 47 chromosomes (XYY) in peripheral blood stutlicx He was the second born of five living

* From the Divisions of Child Development and Metabolism, Children’s Hospital of Los Angeles, Los Angeles, California 90027; and the Department of Pediatrics, University of Southern California School of Medicine and Fairticw State Hospital, Department of Mental Hygiene, Los Angeles, California. This study was supported by grants from the Mental Retardation Division, Social Rehabilitation Services, Department of Health, Education and IVclfare. the Children’s Bureau of the Department of Health, Education and Welfare, Washington, D. C. and the Department of Mental Hygierrr, State of California. Requests for reprints should be addressed to Dr. Charles E. Parker, Division of Child Devcloptnent. Children’s Hospital of Los Angeles, 4650 Sunset Boulevard, Los Angeles, California !)OO27. Manuscript. received November 6, 1968. \.,!I..

47

, NOVEMDEK

1969

801

802

The XYY

Syndrome-Parker

et al.

FIG. 1. Thctc Cews of the propositus show him to bc a tall man gynecomastia, a protruding mandible and a genu valgum.

mal. Mild gynecomastia was present bilaterally and the back was slightly kyphotic without scoliosis. The abdomen was protuberant without organomegaly. The testes were descended bilaterally and firm. The right testis measured 5.9 cm. and the left 5.5 cm. There was bilateral germ valgum, and varicosities of the right medial aspect of the right leg present. The skin showed multiple small, raised, white macules. The neurologic examination was within normal limits except for his obvious mental defect. Blood factors A, A,, B, M, N, C, c, D, E, e, K, Fya were studied and nothing was found to indicate questionable parentage. Serum electrolytes, urea nitrogen, calcium, phosphorus, creatinine, glutamic oxalacetic transaminase, aldolase, T,, T,, alkaline phosphatase and uric acid were normal. Thyroid antibodies (fluorescent technic) were 1 +. The serum testosterone level was 220 mpg. per cent (normal 557 -C 100 mpg. per cent). Paper chromatography of the urine, blood and cerebrospinal fluid revealed normal patterns. The urinary I7-keto and 17-ketogenic steroids were normal as were the pituitary gonadotrophins. Spinal fluid colloidal gold curve, glucose, protein and chloride were nortransferase, mal. Galactose-1-phosphatase uridyl galactokinase, glucose-6-phosphate dehydrogenase,

with

mild

galactose-4-epimerase and pseudocholinesterase (dibucaine number) were in the normal range. The haptoglobin band was 2-2. Roentgenograms of the skull, hands and wrists were within normal limits, and there were no changes suggestive of acromegaly. The electrocardiogram was normal. The electroencephalogram was abnormal and showed generalized moderate cerebral dysrhythmia. Dermatoglyphic examination rescaled a ridge count of 244. 1\Iicroscopic examination of the testis of our patient showed loose interstitial tissue with deficiency of I+dig cells. Some tubules showed active spermatogenesis with spermatid formation whereas others showed a reduced number of germinal epithelial cells. Periodic acid-Schiff and Sudan black B stains were not abnormal. Acid and alkaline phosphatase stains were positive in tubular epithelial cells; alkaline phosphatase stain of capillary endothelium was weaker than usual. Nonspecific (ali) esterase and succinic dehydrogenase stains were weak in tubular cells. No fibrosis, hyalination or thickening of the basement of tubules was noted and no specific cytologic abnormalities (multinicleate or aneuploid cells, etc.) of the germ cells were recognized. The karyotype from a peripheral blood culture of AMERICAN

JOURNAL

OF

MEDICINE

The

XYY

Syndrolne--l’urkcr

PL al

HE,GHT IN FEE’

6’4” t $J”

6’2” 6’

‘-

6’0”

r

5’11”

FIG. 2. Comparative Farnil\ tlw.

heights

of the propositus

Figure 3. The extra Y discernible. Forty-seven &romosomes were fountl in the leukocyte culture, bone marrow antI the testicular fibroblast cultures. ihe

proband

c hromosome

is showr~ in is

easily-

COMMENTS In 1961 Sandberg et al. [I] described the first patient with the XYY syndrome. In 1968 Cowie et al. [Z] reported the syndrome in a prepuberal L$ish child. It occurs also in the Negro [3]. Tile pregnancies and births in the recorded cases were usually normal and there have been no consistent findings in the newborn [4,5]. There are scattered reports of the XYY constitution in conjunction with other syndromes or physical findings. It has been reported in association with Franceschetti’s syndrome 161, Marfan’s syndrome [/“I, Down’s Syndrome [8], webbing of the neck [9], gynecomastia and Ilypogonadism [IO-121, as well as with undescended testes [13], male pseudohermaphroelitism [14,Ii] and a \-ariety of congenital defects [4,5]. The occurrence of XYY in the general population seems to be approximately 0.02 per cent. A low rate is also reported among the mentally ill [I(i,17]. Surveys of prison populations have shown the frequency of XYY males to be between 2 and 3 per cent for those greater tllan G (‘~1 in height ~1R-211. Turner et al. [22] re-

of other

members

of

the

ported none in 100 male newborns whereas Jacobs et al. [19] reported one in 550 randomly selected male babies from two Edinburgh hospitals. Hunter [23] examined the buccal smears of 1,021 school boys. He then examined the karyotypes of twenty-nine boys in this group over the ninetieth percentile in height and found a 10.3 per cent incidence of the XYY constitution. Court Brown et al. [12] surveyed 209 randomlv selected male general practitioners arid fount1 none.

B 2

. 3

4

--

! _a

FIG. 3. This figure shows the karyotype from a blood culture of the proband. The extra Y chromosome is indicated by the arrow.

804

The XYY

Syndrome-Parker TABLE

COMPARISON

Case

No.

SOWCe

Pregnancies

1

[II

6 (1st marriage) 1 set of twins

1

[291

3 (2nd marriage)

2

1311

1 (assumed)

3 4

L3.4 [51

7 (assumed) 2

OF REPORTED

I

PREGNANCIES

Living Children -__ G(bylst wife)

Abortions 1

2 (by 2nd wife) 1

1

et al.

Miscarriages

FATHERED

BY XYY

Normal

MALES

F

M

Abnormal

..

..

4

2

..

1

.

1

.

...

...

1

7

.

1

6

0

1

1

...

...

1

NOTE: Only one fetus has proved to have a chromosomal

At the present time it is not known how many genes regulate sex determination [24], but it is known that the Y chromosome is involved in the development of testicular structure in man [25-271. The further ditierentiation of external genitalia into penis and scrotum is believed to be due to the action of hormones produced by the fetal testes rather than the influence of genes on the Y chromosome in the tissue concerned [24]. Tanner et al. [27] studied the rate of skeletal growth in XXY (Klinefelter’s) syndrome and found it equal to normal XY males. He also noted that the skeletal growth rate in X0 children (Turner’s syndrome) was the same as in normal XX females. He concluded that genes on the Y chromosomes are responsible for the rate of male skeletal maturation. Dronamraju [28] reported that hair on the pinna of the human ear is under the genetic influence of the Y chromosome. This characteristic, apart from male determination, is the only known locus on the Y chromosome. No studies concerning the relative fertility of XYY males have appeared, to our knowledge. Four XYY males have produced offspring; these data are summarized in Table I. All were discovered because of abnormalities in the

abnormality,

Comments One set of twins, sex unknown, 1 died at age 3 as a “blue baby”; the other reported alive and well At 18 yr.; 1 girl has amenorrhea, no breast development, no internal sex organs found at operation Girl, Down’s syndrome (from second marriage) Idiopathic athy

osteoarthrop-

Born cyanotic, exophthalmos, half of calvarium missing, meningocele, spina bifida, bilateral clubbed feet

although five have had congenital defects;

children or grandchildren. The first [1,29] was found accidentally by studying the parents of a child with Down’s syndrome. This man had been married twice and initiated nine pregnancies, in half of which the offspring were abnormal (Table I). The second was discovered in a study of a father and son with idiopathic osteoarthropathy [?I], both of whom had the XYY constitution. The third [?.Z] was found in a study of a grandson with mental retardation, multiple anomalies and tyrosinuria. This man had produced seven children: six normal sons and one normal daughter, who was the mother of the proband. The fourth [5] was studied because his wife had two abnormal pregnancies: a miscarriage at four months and a live child who was born cyanotic with exophthalmos, half the calvarium missing, a meningocele, spina bifida and bilateral club feet. Psychologic Findings. Although our patient was in an institution for the mentally retarded and a number of the patients described have had very low I.Q. scores [/3,16,23,33-371, this is not necessarily a characteristic. Several patients have been described with an XYY constitution and of normal intelligence [1,5,12,19, 23,291. AMERICAN

JOURNAL

OF

MEDICINE

I;IC. 5.

tlilferent

.I ii(‘,c. lJ;ttierits t h;ii:ictcristically tend to by [32,38,3S] from eal.1) exll~c~ln~J\ ;Iggr&ve c~JGltll~ootl and tlie)- 1iai.e difficulty in adjusting IO tit<, 11101 m 01 society ( IY,23]. TJley often have away from school and .I lri,tor) of running l:it~r ~na) get iitto trouble for sexual crimes. I‘lleil. aggrcssi\,eness is so destructive that many .II‘C 11~1al11cto lunction within the limits of \oc iel!, ! t’t tlic majoriLy of offences are against propc’l2\ an(1 not against persons [40]. Price / V,tt\ ;n IIis ytn.\-e\ reported that the XYI malt Iq;rn Iii\ criminal career at an average {IF Ii\ (: VC’;II~ earlier than the controls. Indeed, ill u105t ol tlie (3~~s wcordetl in the world litcratut‘e the patients Irave been from prison ~vdp~ilatiorls (l;.~C)i20,j~,30,t13~7]. /l~,igl//. One characteristic that seems to jtailtl 0111 iu tlie syndrome is height [i,21,23, t/I./;-531. .\lmost all persons reported to date II;I\ e I~cn 01 er (i feet tall and this fact has often been utilizetl when screening a large number of pa tieuts for chromosome studies, both adults antI c hiltlren [23]. Unusual height has also I)ecn noted in other syndromes such as the XX\ 1’ sy~&~ome, in which a double Y chromounit complement is also present [5h]. I3~.slologic Findings. The histologic findings in the testes of patients with XYY syndrome liar-e been reported previously [20,45]. The findings in our patient differ from those of T\;‘iclscanet al. [f 51 who noted Leydig cell hyperplasia. tllickening of the tubular basement membrane anti reduction in germinal cells in a twentysix year old patient. Balodimas et al. tlescribetl similar and more severe changes in the teste:, of a sixty-four year old man, but the significance of their findings is unclear since a J>rotJjer of this patient had essentially tlje same

X-Y bivalcnt spcrmatocylc5

tonhguration in diplotctne

flolll tllre~ pilast,

testicular lesions but a normal kar)ot) J)e. -1‘hey also reported many abnormal sperm cells whereas other investigators have noted noi-ma1 spermatozoa [3h]. To date there aJ>pear to be no clearcut diagnostic features in the testes of patients with XI?’ syndrome although all reports describe findings different from those of the testes in Klinefelter’s syndrome IiS]. 1\8ciosis. Figure 4 shows o11e ot many Ijri1na1-y spermatocytes seen at diplotenediakinesis which were obtained from a unilateral testic ular biopsy specimen. During meiosis the X alld Y chromosomes normally pair end to end [34, .50]. A typical bex JIivalent from tliis patient indicated by the arrow appears to contain only one Y chromosome. Additional nol,mal appearing sex chromosome bivalents arc sho~vn in Figure 5. These observations support tile findings in a recent study which indicate that the second Y chromosome is eliminated by relet tive nondis.junction prior to spermatogenesis 15 31. Fmtzlization and Expected Otf.spring-. Figure 6 shows the four types of gametes and their ratios which would be expected on rJlc basis of random segregation of the X and J’ c-hi~cmo‘il,h,L~U. \!,x,!PK v\

YYYFnPitn >.YY

1Xx

PROCENY NOW

2

FEMALE

FIG. 6. The four possible

x..Y

KLINEFmTmS

I

\yi

?

w

NONXAL

MALE

zygotes and their pregnancies resuIting from a union of an XYY male and a normal XX female if segregation of X and two presumed Y chromosomes is random.

806

The XYY Syndrome-Parker

somes. However, it is uncertain at this time whether segregation of the extra Y is random or even whether it is present during meiosis [32]. The observed incidence of abnormal pregnancies has ranged from 0 [32] to 100 per cent [5], although in only one of the twenty reported cases has a chromosomal abnormality been proved in the fetus (Table I). Dermatoglyphics. Most studies report that an excess of sex chromosome material leads to a decrease in the ridge count on the fingers [8,56-601. The mean value for normal males reported by Holt [30] ils 145. Penrose [SS] reported ridge counts in two XYY patients of 192 and 133. Our patient had a ridge count of 244 [41]. A total ridge count higher than normal is generally expected with Turner’s (X0) syndrome [(ill. Uchida et al. [62] found the ulnar triradii absent in two cases of XYY syndrome. However, Malvalwala et al. [41] reported their presence in an extensive report on the dermatoglyphics of this patient. There appears to be no diagnostic dermatoglyphic patterns for the XYY syndrome. Epilepsy and abnormal Laboratory Data. electroencephalograms have been reported in this syndrome [63] and a study of the electrocardiograms in twenty persons with the XYY syndrome has recently been reported by Price et al. [64] in which they found P-R interval the presence of secondary R prolongation, waves in V leads and reduction of the size and notching of the X wave in lead V,. The plasma testosterone level of 200 mg. per 100 ml. is at variance with that reported by Welch 1651 and Ismail et al. [44]. Urinary gonadotrophins were normal, confirming the findings by Balodimos and associates [IO]. Implications. The influence of heredity upon behavior has been debated for many years. Most workers have concluded that environmental factors are of greater importance than genetic ones [66]. This syndrome provides strong support for the concept of a dominant role of the genetic component [3#,42] in some instances. The internist, the pediatrician, the general practitioner and of course the child psychiatrist sees many school problems in his office. If a tall, aggressive, delinquent male child or young adult should present himself in the office and if careful investigation indicates that the parents and siblings do not manifest these traits, a karyotype should be obtained.

et al.

There are also far-reaching implications in forensic medi,cine. The possibility of personality deviation and criminal traits due to an abnormal chromosomal constitution opens up many unanswered questions: questions of responsibility and questions of punishment. This aspect has received considerable attention recently in the lay press [67-701. Acknowledgment: We wish to acknowledge the contributions of the following personnel of the Children’s Hospital of Los Angeles: Richard Koch, M.D. for his support during the project and his help with the manuscript and to the following people for their assistance in various laboratory tests: George Donnell, M.D., Benjamin H. Landing, M.D., Denman Hammond, M.D., William R. Bergren, PH.D., Kenneth N. F. Shaw, PH.D., Miss Susan Hayes and Mrs. Anna Derencsenyi. We would also like to acknowledge the kind assistance of Claude J. Migeon, M.D., of Johns Hopkins University, Baltimore, Maryland, who performed the testosterone determinations. REFERENCES A. A., KOEPF, G. F., ISHIHARA, T. and HAUSCHKA, T. S. An XYY human male. Lancet, 2:

1. SANDBERG,

488,196l. 2. COWIE, J. and KAHAN, J. XYY constitution in prepubertal child. Brit. M. J., 1: 748, 1968. 3. TELFER, M. A., BAKER, D. and LONGTIN, L. YY syndrorne in an American negro. Lancet, 1: 95, 1968. 4. VIGNE?TI, P., CAPOTOTTI, L. and FERRANTE,E. XYY chromosomal constitution with genital abnormality: girl XYY. Lancet, 2: 588, 1964. 5. WILTON, E. XYY male. South African M. J., 41: 284, 1967. 6. KOSENOW,W. and PFEIFFER,R. A. YY syndrome with multiple malformations. Lancet, 1: 1375, 1966. 7. HUSTINX, T. W. J. and VAN OLPHEN, A. H. F. An XYY chromosome pattern in a boy with Marfan’s syndrome. Genetica, 34: 262, 1963. 8. UCHIDA, I. A., RAY, M. and DUNCAN, B. P. 21 trisomy with an XYY sex chromosome complement. J. Pediat., 69: 295, 1966. 9. KELLY, S., ALMY, R. and BERNARD,M. Another XYY phenotype. Nature, 215: 405, 1967. 10. BALODIMOS,M. C., LISCO, H., IRWIN, I., MERRILL, W. and DINGMAN, J. F. XW karyotype in a case of familial hypogonadism. J. Chin. Endocrinol., 26: 4: 452, 1966. 11. BLJCKTON,K. E., BOND, J. A. and MCBRIDCE, J. A. An XYY sex chromosome complement in a male with hypogonadism: human chromosome. Newsletter, 8: 11, 1962. 12. COURT BROWN, W. M., HARNDEN,D. G., JACOBS,P. A., MACLEAN, N. and MANTLE, D. J. Abnormalities of the sex chromosome complement on man: case AMERICAN

JOURNAL

OF

MEDICINE

The

XYY

Syndrome-Parker

I :. bI~.~c:c. XI~O,hf., I)ivn 5, P., BOTT, RI. G. and ScHu-rr, T\. Rlenral tleficienc\ and undescended testis in IWC, Irlalc~ with XqY sex chromosomes. Folia Ilcr-eri. ei Pall?., 11: 211, 1962. I 1. I.RA~KS, Ii. C., BUNTING, K. 11’. and ENGEL, I. Male l~~~~~~lohtrrnl;lphrodism with XYY sex chromeS~~,,,~S.I. Clin. Enrloclmol., 27: 1623, 1967. ii. J’IC.XITI, P., CAPOTOTTI, L. and FERUNTE, E. A case of male pseudohermaphroditism with 47 chromosomes. Mi?ZeWa pediat., 17: 10: 596, 1965. 16. C.ZWY, M. D., BLANK, C. E.. STREET, D. R. K., SECALL, I. I,. UCDOU~;ALL, J II., MCGRATH, P. 1. and hhlNhf-R, j. I.. YI' ct~tomOsOmes and antiSO&l beII;~Eior. I.umrl, 2: 851). 19G6. I;. ‘IVIF.NER, E., ST-THERLANI~.G., BARTHOLOMEW, A. and JI[~sou, B. XYY males in a Melbourne prison. / U?!W/, 1: 150. 1968. 18. ,I 1~w%), I? A.. BRUNTON, M., MELVILLE, hi. hl., BIU~TAI~, R. 1’. and MCCLEMONT, W. F. Aggres\i\c I)eh:lriolll-rllental subnormality and the X\‘Y rll.~le. Siltrit-/). 208: 1351, 1966. I!). 1U:OKS, I’. A., PRICE.12;.H. and COURT BROWN, W. 1T Cltrort~osc~~nc studies of men in a niaximuul \c.cilrir\ hospital. Anl2. Human Genet., 31: 339. i!l68. 20. I’RIc.~., I\‘. H. and WHAIMORE, P. B. Behavior dis!)rtlers anrl pattern of crime among XYY males id(~nlilictf al n maxirrlum security flospital. Hrii. .\I. I.. I : 533, 1967. i’l. I I I.FI.K. hl. A.. BI\ICEK, D., CLARKE, C. R. and IrRhm TIEI~OI.O, C. G., HERRLIN, K. M., LIVADITIS, 1.. PEI+WON. 11. and TILLINGER, K. G. Cytogcnetiral and clinical investigation in four subjects with inomnlies of sexual development: XOjXYjXYY llloyaic. .4nn. Human Genet., 29: 281, 196G. 25. Bl~<,r.CLl?, A. and AAGFNES, 0. Role of Y chromo\1~1c in clc\elopnrcn t of testicular structures. ! nnwt, 2: 259, 1964. 26. ]\WBS. P. A. and ROSS. A. Structural abnormalities d)f 11~ ‘Y’ cl~ron~oson~c in man. Nature, 210: 352,

I!Nx 17. T.\NNFK,

M., PRADER, A., HABICH, H. and FERGI.. M. A. Genes on the Y chromosome in. Ilnencing rate of maturation in man: skeletal age >cudies in children with Klinefelter’s (XYY) and 7.nrner‘s syndromes (X0). Lancet, 2: 141, 1!>59. 18. I)RONAMRAJIJ, K. R. Hypertrichosis of the pinna of the human ear, Y-linked pedigrees. J. Genet., 57: “10, I!Mx t’!). HUWHKA, T. S., HASSON, J. E., GOLDSTEIN, N. M., KOWF, G. F. and SAI\‘DBERG,A. An XYY man with progenv indicating familial tendency to nondisjunction. .4m. J. Human Genet., 14: 22, 1962. J.

>ON-SMITH,

var.

4’.

>OVEMIrER

1969

rt al.

30. HOI,T, S. B. Quantitative genetics of tingc~pl in1 patterns. &it. Al. Bull., 17: 247, 1961. 31. TZONEVA-MANEVA, hf. T., BOSAJIEYA, E. and PEIROX, B. Chromosomal abnormalities in itliopathic osteoardlropathv. Lancrt, 1: 1000, 1966. 32. THOMPSON, H., MFLNYK, J, and HFCIIT. F. Reproduction :antl meiosis in XYY. Lancet, 2: 831, 1967. 33. CASEY, RI. D., SECALL, L. J., CTRFET, 1). K. K. and IIL.4Kk, C. E. Sex chrotnosomc abnormalities in two state hospitals for patient requiring special security. Nnture, 209: 641, 196G. 34. FORSSMAN, H. and GUNNAR, H. Chromosome and antisocial behavior. Lancet, 2: 282. 1966. 35. HOPE, K., PHILIP, A. E. and LOLCI-~RAN, 1‘ M. Psvchological characteristics associated with XYY sex chromosome complement in a state mental hospital. firit. I. Psyclliat., 113: 495, 196i. 36. RICCI, K. and MAIACRANE. P. .4n XI’\’ huntan rnalr. Lo?fcer I I: 71’1. ‘. 1964. 37. Lead article. The YY syndrome. I_UJIW(. 1: 583, 19tifi. 38. MIWZ~R, R., PERC.AMMENT, E., BARLOW, S. and Sxro, H. The YY syndrome. J. Pediat., 72: 572, 1968. 39. PRICT, IV. H. and W’HATMOKE, I’. B. Criminal beIlavior ant1 111~XYl’ male. ,\-afi~r. 21 3: 8 15, 1967. 40. PRICE, I\‘. It STKO\‘(;, 1. ;\., \,.H.\T.\IOKE, 1’. l$. and .\ICCL,EhlOST, \v. 1:. Criminal patients wilh XYY sex chlomo\o111e colnplc~ent. I.rr?!cet, I 565, I’)G’,. 41. M~I.~,ZLWAIA, J., P\RKIK. C. E. and MFLNYK;, J. I)crtilatl,gl~pllics in n patient rvith I jlc \iYY y-

tl!Wlll~. I,rr. 1. Pi,l’.\. .IJ?/ir,-oprd..::o: 200 21-1, 1969. 4”. CR \\v,‘OKn,

J. 1’. Secondar! $<‘\ cIlatxctcI.l.tic\. 1365, 1!)66. 43. HLLTEN, >I., LINDSTTN, 1.. 111~6, PEK-\IIN(., 1.. atltl FKACCAKO, hi. The XI. biralent atnl llurnan rllale meiosis. ;4?2?a. Human GCIZC/., 30: 119.I066. 44. ISMAIL, A A. A., HARKNTSS, R. A.. KIRKHAM, K. f;,., I cr/twt, 2:

48. Bocz~owsar, K. and C.~SW, M. D. Pattern of DNA replication of the sex chromosomes in three males: two with XYY and one with XXYY karyor.ype. Nature, 213: 92S, 1967. 49. GOODMAN, R. M., SMITH, W. S. and ;\IIGEON,C. J. Sex OII omosomc abnormalities. Nnlure, 226: 942, 1967. 50. HLNTER, H. YY chromosomes and Klinefelter’s svntlronic~. Lancct, 1: 984, 1966. 51. P.wK, IV. I\:. The YY syndrome. Lnncet. 2: 1468, 1966. 52. STOECRENIUS, M. A probabIe Y isochromosome in father and son of tall structure. Lancet, 2: 391, 1966. 53. KAJII, T.. NEU, R. L. and GARDNER, L. L. XYjXYY mosaicism in a prepubertal boy with tall stature, prqgnathism and malformarions of the hands. Pcrlio tries, 41: 5, 1968.

The XYY Syndrome-Parker 54. WATERMAN, D. F., LONDON, J.. VALDMANIS, A. and MANN, J. D. The XXYY

chromosome

constitution.

Am. J. Dis. Child., 3: 421, 1966. 55. SANDBERG,A. A., ISHIHARA, T., CROSSWHITE,L. H. and KOEPF, G. F. XYY genotype. New England J. Med., 268: 585, 1963. 56. ALTER, M. Is hyperploidy of sex chromosomes associated with reduced finger ridge count? Am. J. Human Genet., 17: 473, 1965. 57. ALTER, M., GORLIN, R., YUNIS, J., PEAGLER, F. and

62.

63. 64.

BRUHL, H. Dermatoglyphics in XXYY Klinefelter’s syndrome. Am. J. Human Genet., 18: 507, 1966. 58. FANG, T. C. A comparative study of the a-b ridge count on the palms of mental defectives and the general British population. J. Ment. SC., 95: 945,

65.

1949. 59. PENROSE, L. S., CANTAB, M. D. and MCGILL, F. R. S., D.Sc. Fingerprint pattern and the sex-chromosomes. Lancet, 1: 298. 1967. 60. PERSON,T. An XYY man and his relatives. 1. Me&. Deficiency & Res., 2: 4; 239, 1967. 61. HOLT, S. B. and LINDSTEN,J. Dermatoglyphic anom-

67. 68.

66.

69.

70.

et al.

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