47,XYY syndrome

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XYY syndrome is an aneuploidy (abnormal number) of the sex chromosomes in which a human male receives an extra Y chromosome, giving a total of 47 chromosomes instead of the more usual 46. This produces a 47,XYY karyotype.

Some medical geneticists question whether the term "syndrome" is appropriate for this condition because its phenotype is normal and the vast majority (an estimated 97% in the UK) of 47,XYY males do not know their karyotype.[1][2]

Physical traits

Most often, the extra Y chromosome causes no unusual physical features or medical problems. Since XYY is not characterized by distinct physical features, the condition is usually detected only during genetic analysis for another reason.

47,XYY boys have an increased growth velocity during earliest childhood, with an average final height approximately 7 cm above expected final height.[3] The increased gene dosage of three X/Y chromosome pseudoautosomal region (PAR1) SHOX genes has been postulated as a cause of the increased stature seen in all three sex chromosome trisomies: 47,XXX, 47,XXY, and 47,XYY.[4]

Severe acne was noted in a very few early case reports, but dermatologists specializing in acne now doubt the existence of a relationship with 47,XYY.[5]

Testosterone levels (prenatally and postnatally) are normal in 47,XYY males.[6] Most 47,XYY males have normal sexual development and usually have normal fertility.

Behavioral characteristics

47,XYY boys have an increased risk of learning difficulties (in up to 50%) and delayed speech and language skills.[1][7][8][9][10][11][12][13][14] In comparison, a national survey of US children conducted in 2004 for the CDC found that 10% of all boys had a learning disability.[15]

As with 47,XXY boys[16] and 47,XXX girls, IQ scores of 47,XYY boys average 10–15 points below their siblings.[7][8][10][12][13] For context, this amount of variation—an average difference of 12 IQ points—often occurs naturally between children in the same family.[7][17]

The Denver Family Development Study led by Arthur Robinson[18] found that in 14 prenatally diagnosed 47,XYY boys (from high socioeconomic status families), IQ scores available for 6 boys ranged from 100–147 with a mean of 120.[19] For the 11 of 14 boys with siblings, in 9 instances their siblings were stronger academically, but in one case they were performing equal to and in another case superior to their brothers and sisters.[19]

Developmental delays and behavioral problems are also possible, but these characteristics vary widely among affected boys and men, are not unique to 47,XYY and are managed no differently than in 46,XY males.[8][10][14] Aggression is not seen more frequently in 47,XYY males.[1][7][8][10][11][13]


47,XYY is not inherited, but usually occurs as a random event during the formation of sperm cells. An error in chromosome separation during anaphase II (of meiosis II) called nondisjunction can result in sperm cells with an extra copy of the Y chromosome. If one of these atypical sperm cells contributes to the genetic makeup of a child, the child will have an extra Y chromosome in each of the body's cells.[14][20]

In some cases, the addition of an extra Y chromosome results from nondisjunction during cell division during a post-zygotic mitosis in early embryonic development. This can produce 46,XY/47,XYY mosaics.[14][20]


About 1 in 1,000 boys are born with a 47,XYY karyotype. The incidence of 47,XYY is not affected by advanced paternal or maternal age.[1][10][12]



In April 1956, Hereditas published the discovery by cytogeneticists Joe Hin Tjio and Albert Levan at Lund University in Sweden that the normal number of chromosomes in diploid human cells was 46—not 48 as had been believed for the preceding thirty years.[21] In the wake of the establishment of the normal number of human chromosomes, 47,XYY was the last of the common sex chromosome aneuploidies to be discovered, two years after the discoveries of 47,XXY,[22] 45,X,[23] and 47,XXX[24] in 1959. Even the much less common 48,XXYY[25] had been discovered in 1960, a year before 47,XYY.

Screening for those X chromosome aneuploidies was possible by noting the presence or absence of "female" sex chromatin bodies (Barr bodies) in the nuclei of interphase cells in buccal smears, a technique developed a decade before the first reported sex chromosome aneuploidy.[26] An analogous technique to screen for Y chromosome aneuploidies by noting supernumerary "male" sex chromatin bodies was not developed until 1970, a decade after the first reported sex chromosome aneuploidy.[27]

The first published report of a man with a 47,XYY karyotype was by internist and cytogeneticist Avery Sandberg and colleagues at Roswell Park Memorial Institute in Buffalo, New York in 1961. It was an incidental finding in a normal 44-year-old, 6 ft. [183 cm] tall man of average intelligence who was karyotyped because he had a daughter with Down syndrome.[28] Only a dozen isolated 47,XYY cases were reported in the medical literature in the four years following the first report by Sandberg.[29]

Then, in December 1965 and March 1966, Nature and The Lancet published the first preliminary reports by British cytogeneticist Patricia Jacobs and colleagues at the MRC Human Genetics Unit at Western General Hospital in Edinburgh of a chromosome survey of 315 male patients at The State Hospital outside Carstairs, Lanarkshire—Scotland’s only special security hospital for the developmentally disabled—that found nine patients, ages 17 to 36, averaging almost 6 ft. in height (avg. 5'11", range: 5'7" to 6'2"), had a 47,XYY karyotype, and mischaracterized them as aggressive and violent criminals.[29][30][31][32] Over the next decade, almost all published XYY studies were on height-selected, institutionalized XYY males.[10]

In January 1968 and March 1968, The Lancet and Science published the first U.S. reports of tall, institutionalized XYY males by Mary Telfer, a biochemist, and colleagues at the Elwyn Institute.[33] Telfer found five tall, developmentally disabled XYY boys and men in hospitals and penal institutions in Pennsylvania, and since four of the five had at least moderate facial acne, jumped to the erroneous conclusion that acne was a defining characteristic of XYY males.[33] After learning that convicted mass murderer Richard Speck had been karyotyped, Telfer not only incorrectly assumed the acne-scarred Speck was XYY, but leapt to the egregiously false conclusion that Speck was the archetypical XYY male—or "supermale" as Telfer referred to XYY males outside of peer-reviewed scientific journals.[34]

In April 1968, The New York Times—using Telfer as a main source—introduced the XYY genetic condition to the general public in a three-part series on consecutive days that began with a Sunday front-page story about the planned use of the condition as a mitigating factor in two murder trials in Paris[35] and Melbourne[36]—and falsely reported that Richard Speck was an XYY male and that the condition would be used in an appeal of his murder conviction.[31][37] The series was echoed the following week by articles—again using Telfer as a main source—in Time and Newsweek,[38] and six months later in The New York Times Magazine.[39]

In December 1968, the Journal of Medical Genetics published the first XYY review article—by Michael Court Brown,[40] director of the MRC Human Genetics Unit—which reported no overrepresentation of XYY males in nationwide chromosome surveys of prisons and hospitals for the developmentally disabled and mentally ill in Scotland, and concluded that studies confined to institutionalized XYY males may be guilty of selection bias, and that long-term longitudinal prospective studies of newborn XYY boys were needed.[29]

In May 1969, at the annual meeting of the American Psychiatric Association, Telfer and her Elwyn Institute colleagues reported that case studies of the institutionalized XYY and XXY males they had found convinced them that XYY males had been falsely stigmatized and that their behavior may not be significantly different from chromosomally normal 46,XY males.[41]

In June 1969, the National Institute of Mental Health (NIMH) Center for Studies of Crime and Delinquency held a two-day XYY conference in Chevy Chase, Maryland.[42] In December 1969, with a grant from the NIMH Center for Studies of Crime and Delinquency, cytogeneticist Digamber Borgaonkar at Johns Hopkins Hospital began a chromosome survey of (predominantly African-American) boys ages 8 to 18 in all Maryland institutions for delinquent, neglected, or mentally ill juveniles, which was suspended from February–May 1970 due to a American Civil Liberties Union (ACLU) lawsuit about the lack of informed consent.[43] Concurrently, through 1974, psychologist John Money at Johns Hopkins Hospital experimented on thirteen XYY boys and men (ages 15 to 37) in an unsuccessful attempt to treat their history of behavior problems by chemical castration using high-dose Depo-Provera—with side-effects of weight gain (avg. 26 lbs.) and suicide.[44]


In December 1969, Lore Zech at the Karolinska Institute in Stockholm first reported intense fluorescence of the AT-rich distal half of the long arm of the Y chromosome in the nuclei of metaphase cells treated with quinacrine mustard.[45] In April 1970, Peter Pearson and Martin Bobrow at the MRC Population Genetics Unit in Oxford and Canino Vosa at the University of Oxford reported fluorescent "male" sex chromatin bodies in the nuclei of interphase cells in buccal smears treated with quinacrine dihdyrochloride, which could be used to screen for Y chromosome aneuploidies like 47,XYY.[46]

In June 1970, The XYY Man was published—the first of seven Kenneth Royce spy novels whose fictional tall, intelligent, nonviolent XYY hero was a reformed expert cat burglar recruited by British intelligence for dangerous assignments—and later adapted into a thirteen-episode British summer television series broadcast in 1976 and 1977.[47] In other fictional television works, a January 1971 episode "By the Pricking of My Thumbs ..." of the British science fiction TV series Doomwatch featured a 16-year-old XYY boy expelled from school because of his genetic condition,[48] a November 1993 episode "Born Bad" of the American police procedural TV series Law & Order portrayed a 14-year-old XYY sociopathic murderer,[49] and the May 2007 season finale episode "Born To Kill" of the American police procedural TV series CSI: Miami depicted a 34-year-old XYY serial killer.[50] The false stereotype of XYY boys and men as violent criminals has also been used as a plot device in the horror films Il gatto a nove code in February 1971 (dubbed into English as The Cat o' Nine Tails in May 1971) and Alien³ in May 1992.[31][32]

In December 1970, at the annual meeting of the American Association for the Advancement of Science (AAAS), its retiring president, geneticist H. Bentley Glass, cheered by the legalization of abortion in New York,[51] envisioned a future where pregnant women would be required by the government to abort XYY "sex deviants."[52] Mischaracterization of the XYY genetic condition was quickly incorporated into high school biology textbooks[53] and medical school psychiatry textbooks,[54] where misinformation still persists decades later.[32]

In the late 1960s and early 1970s, screening of consecutive newborns for sex chromosome abnormalities was undertaken at seven centers worldwide: in Denver (Jan 1964–1974), Edinburgh (Apr 1967–Jun 1979), New Haven (Oct 1967–Sep 1968), Toronto (Oct 1967–Sep 1971), Aarhus (Oct 1969–Jan 1974, Oct 1980–Jan 1989), Winnipeg (Feb 1970–Sep 1973), and Boston (Apr 1970–Nov 1974).[55] The Boston study, led by Harvard Medical School child psychiatrist Stanley Walzer at Children's Hospital, was unique among the seven newborn screening studies in that it only screened newborn boys (non-private-ward newborn boys at the Boston Hospital for Women) and was funded in part by grants from the NIMH Center for Studies of Crime and Delinquency.[32][56]

In 1973, child psychiatrist Herbert Schreier at Children’s Hospital told Harvard Medical School microbiologist Jon Beckwith of Science for the People that he thought Walzer’s Boston XYY study was unethical; Science for the People investigated the study and filed a complaint with Harvard Medical School about the study in March 1974.[32] In November 1974, when the Harvard Medical School committee on medical research recommended that the study continue, Science for the People went public with their objections to the Boston XYY study in a press conference and a New Scientist article alleging inadequate informed consent, a lack of benefit (since no specific treatment was available) but substantial risk (by stigmatization with a false stereotype) to the subjects, and that the unblinded experimental design could not produce meaningful results regarding the subjects' behavior.[32][56] Changes to informed consent procedures and pressure from additional advocacy groups, including the Children's Defense Fund, led to the 1975 discontinuation of the last active U.S. newborn screening programs for sex chromosome abnormalities in Boston and Denver.[32][56]

In August 1976, Science published a retrospective cohort study by Educational Testing Service psychologist Herman Witkin and colleagues that screened the tallest 16% of men (over 6'0" in height) born in Copenhagen from 1944–1947 for XXY and XYY karyotypes, and found an increased rate of minor criminal convictions for property crimes among sixteen XXY and twelve XYY men may be related to the lower intelligence of those with criminal convictions, but found no evidence that XXY or XYY men were inclined to be aggressive or violent.[57]

1980s and later

The March of Dimes sponsored five international conferences in June 1974, November 1977, May 1981, June 1984, and June 1989 and published articles from the conferences in book form in 1979, 1982, 1986, and 1991 from seven longitudinal prospective studies on the development of over 300 children and young adults with sex chromosome abnormalities identified in the screening of almost 200,000 consecutive births in hospitals in Denver, Edinburgh, New Haven, Toronto, Aarhus, Winnipeg, and Boston from 1964 to 1975.[55][58] These seven studies—the only unbiased studies of unselected individuals with sex chromosome abnormalities—have replaced the older, biased studies of institutionalized individuals in understanding the development of individuals with sex chromosome abnormalities.[10][59]

In May 1997, Nature Genetics published the discovery by Ercole Rao and colleagues of the X/Y chromosome pseudoautosomal region (PAR1) SHOX gene, haploinsufficiency of which leads to short stature in Turner syndrome (45,X).[60] It was subsequently postulated that the increased gene dosage of three SHOX genes leads to tall stature in the sex chromosome trisomies 47,XXX , 47,XXY, and 47,XYY.[4] In September 2007, the American Journal of Medical Genetics published a report by Marquis Vawter and colleagues that the increased gene dosage of three pseudoautosomal region PAR1 GTPBP6 genes in Klinefelter's syndrome (47,XYY) was correlated with decreased verbal IQ.[16]

See also


  1. 1.0 1.1 1.2 1.3 Graham, Gail E.; Allanson, Judith E.; Gerritsen, Jennifer A. (2007). "Sex chromosome abnormalities", in Rimoin, David L.; Connor, J. Michael.; Pyeritz, Reed E.; Korf, Bruce R. (eds.): Emery and Rimoin's principles and practice of medical genetics, 5th, Philadelphia: Churchill Livingstone Elsevier, 1038–1057. ISBN 0443068704. 
  2. Template:Cite conference
  3. Nielsen, Johannes (1998). How is height growth?. XYY males. An orientation. The Turner Center, Aarhus Psychiatric Hospital, Risskov, Denmark. Retrieved on 2008-01-11.
  4. 4.0 4.1 Cohen, Pinchas; Shim, Melanie (2007). "Hyperpituitarism, tall stature, and overgrowth syndromes", in Kliegman, Robert M.; Behrman, Richard E.; Jenson, Hal B.; Stanton, Bonita F. (eds.): Nelson textbook of pediatrics, 18th, Philadelphia: Saunders, 2303–2307. ISBN 1416024506.  p. 2304: Table 561-1. Differential diagnosis of tall stature and overgrowth syndromes. Postnatal overgrowth leading to childhood tall stature—includes: Klinefelter syndrome (XXY), SHOX excess syndromes, XYY.
  5. Plewig, Gerd; Kligman, Albert M. (2000). Acne and rosacea, 3rd, Philadelphia: Springer-Verlag, 377. ISBN 3540667512. 
  6. Ratcliffe, Shirley G.; Read, Graham; Pan, Huiqi; Fear, Claudine; Lindenbaum, Richard; Crossley, Jennifer (September 1994). "Prenatal testosterone levels in XXY and XYY males". Horm Res 42 (3): 106–109. doi:10.1159/000184157. PMID 7995613.
  7. 7.0 7.1 7.2 7.3 Guy's Hospital Clinical Genetics Department (2001, 2005). The XYY condition. Scottish Genetics Education Network (ScotGEN). Retrieved on 2009-09-12.
  8. 8.0 8.1 8.2 8.3 Linden, Mary G.; Bender, Bruce G.; Robinson, Arthur (June 1, 2002). "Genetic counseling for sex chromosome abnormalities". Am J Med Genet 110 (1): 3–10. doi:10.1002/ajmg.10391. PMID 12116264.
  9. Gardner, R.J. McKinlay; Sutherland, Grant R. (2004). Chromosome abnormalities and genetic counseling, 3rd, Oxford: Oxford University Press, 29–30, 42, 199, 207, 257, 263, 393, 424–430. ISBN 0195149602. 
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 Milunsky, Jeff M. (2010). "Prenatal diagnosis of sex chromosome abnormalities", in Milunsky, Aubrey; Milunsky, Jeff M. (eds.): Genetic disorders and the fetus : diagnosis, prevention and treatment, 6th, Oxford: Wiley-Blackwell, 273–312. ISBN 1405190876. 
  11. 11.0 11.1 Beltz, Carin Lea (2005). "XYY syndrome", in Narins, Brigham (ed.): The Gale encyclopedia of genetic disorders, 2nd, Detroit: Thomson Gale, 1369–1371. ISBN 1414403658. 
  12. 12.0 12.1 12.2 Firth, Helen V.; Hurst, Jane A.; Hall, Judith G. (2005). Oxford desk reference: clinical genetics. Oxford: Oxford University Press, 498–499. ISBN 0192628968. 
  13. 13.0 13.1 13.2 Nussbaum, Robert L.; McInnes, Roderick R.; Willard, Huntington F. (2007). Thompson & Thompson genetics in medicine, 7th, Philadelphia: Saunders Elsevier, 105–107. ISBN 1416030808. 
  14. 14.0 14.1 14.2 14.3 National Library of Medicine (January 3, 2010). Genetics Home Reference: 47,XYY syndrome. National Library of Medicine. Retrieved on 2010-01-13.
  15. Bloom, Barbara; Dey, Achintya N. (February 2006). "Summary health statistics for U.S. children: National Health Interview Survey, 2004". Vital Health Stat 10 (227): 1–85. National Center for Health Statistics. PMID 16532761.
  16. 16.0 16.1 The increased gene dosage of three pseudoautosomal region PAR1 GTPBP6 genes in Klinefelter's syndrome (47,XYY) has been correlated with decreased verbal IQ.
  17. Scarr, Sandra; Deater-Deckard, Kirby (1997). "Family effects on individual differences in development", in Luthar, Suniya S. (ed.): Developmental psychopathology: perspectives on adjustment, risk, and disorder. Cambridge: Cambridge University Press, 119. ISBN 0521477158. 
  18. Robinson, Arthur (April 1990). "Living history: an autobiography of Arthur Robinson". Am J Med Genet 35 (4): 475–480. doi:10.1002/ajmg.1320350406. PMID 2185631.
  19. 19.0 19.1 Linden, Mary G.; Bender, Bruce G. (June 1, 2002). "Fifty-one prenatally diagnosed children and adolescents with sex chromosome abnormalities". Am J Med Genet 110 (1): 11–18. doi:10.1002/ajmg.10394. PMID 12116265.
  20. 20.0 20.1 Robinson, David O.; Jacobs, Patricia A. (November 1, 1999). "The origin of the extra Y chromosome in males with a 47,XYY karyotype". Hum Mol Genet 8 (12): 2205–2209. doi:10.1093/hmg/8.12.2205. PMID 10545600.
  21. Tjio, Joe Hin; Levan, Albert (April 1956). "The chromosome number of man". Hereditas 42 (1): 1–6.
  22. Jacobs, Patricia A.; Strong, John A. (January 31, 1959). "A case of human intersexuality having a possible XXY sex-determining mechanism". Nature 183 (4657): 302–3. doi:10.1038/183302a0. PMID 13632697.
  23. Ford, Charles E.; Jones, Kenneth W.; Polani, Paul E.; de Almeida, José Carlos Cabral; Briggs, John H. (April 4, 1959). "A sex-chromosome anomaly in a case of gonadal dysgenesis (Turner's syndrome)". Lancet 273 (7075): 711–3. doi:10.1016/S0140-6736(59)91893-8. PMID 13642858.
  24. Jacobs, Patricia A.; Baikie, Albert G.; Court Brown, W. Michael; MacGregor, Thomas N.; Harnden, David G. (September 26, 1959). "Evidence for the existence of the human "super female"". Lancet 274 (7100): 423–5. doi:10.1016/S0140-6736(59)90415-5. PMID 14406377.
  25. Muldal, Sylfest; Ockey, Charles, H. (August 27, 1960). "The "double male": a new chromosome constitution in Klinefelter's syndrome". Lancet 276 (7147): 492–3. doi:10.1016/S0140-6736(60)91624-X.
  26. Barr, Murray, L.; Bertram, Ewart G. (April 30, 1949). "A morphological distinction between neurones of the male and female, and the behaviour of the nucleolar satellite during accelerated nucleoprotein synthesis". Nature 163 (4148): 676–677. doi:10.1038/163676a0. PMID 18120749.
  27. . (June 6, 1970). "In pursuit of the Y chromosome". Nature 226 (5249): 897. doi:10.1038/226897a0. PMID 4192294.
  28. Sandberg, Avery A.; Koepf, George F.; Ishihara, Takaaki; Hauschka, Theodore S. (August 26, 1961). "An XYY human male". Lancet 278 (7200): 488–489. doi:10.1016/S0140-6736(61)92459-X. PMID 13746118.
  29. 29.0 29.1 29.2 Court Brown, W. Michael (December 1968). "Males with an XYY sex chromosome complement". J Med Genet 5 (4): 341–59. doi:10.1136/jmg.5.4.341. PMID 4890326.
  30. Jacobs, Patricia A.; Brunton, Muriel; Melville, Marie M.; Brittain, Robert P.; McClemont, William F. (December 25, 1965). "Aggressive behavior, mental sub-normality and the XYY male". Nature 208 (5017): 1351–2. doi:10.1038/2081351a0. PMID 5870205.
  31. 31.0 31.1 31.2 Green, Jeremy (1985). "Media sensationalism and science: The case of the criminal chromosome", in Shinn, Terry; Whitley, Richard (eds.): Expository science: Forms and functions of popularisation. Dordrecht, Holland: D. Reidel Pub. Co., 139–161. ISBN 9027718318. 
  32. 32.0 32.1 32.2 32.3 32.4 32.5 32.6 Beckwith, Jonathan R. (2002). "The myth of the criminal chromosome", Making genes, making waves: A social activist in science. Cambridge, Mass.: Harvard University Press, 116–134. ISBN 0674009282. 
  33. 33.0 33.1 Telfer, Mary A.; Baker, David; Longtin, Lucien (January 13, 1968). "YY syndrome in an American Negro". Lancet 291 (7533). doi:10.1016/S0140-6736(68)90107-4. PMID 4169701.
  34. Telfer, Mary A. (November-December 1968). "Are some criminals born that way?". Think 34 (6): 24–8. ISSN 0040-6112.
    Why do men commit crimes of violence? For some, the urge to violence may be inborn—traced to something called the Y chromosome...
    Once in every 500 male births, for example, the sex chromosome complement is XXY rather than XY, thus erring in the direction of femaleness. The resulting individual, called a Klinefelter male, is usually retarded, unusually tall and sterile.
    Erring in the other direction, however, is the XYY complement resulting in the "supermale." He is also unusually tall and somewhat retarded, but appears to be highly, perhaps too highly, sexually motivated...
    We were intrigued by Dr. Jacobs' contention that an extra Y chromosome results in tall stature, mild mental retardation, and severely disordered personality characterized by violent, aggressive behavior. We therefore planned to confirm and extend her studies.

    Syndrome Status for the XYY
    The XXY male has long been thought to display a constellation of symptoms that makes him diagnosable; that is, he has achieved syndrome status. It would seem that the XYY male is fast achieving similar status. His symptoms, as we and other laboratories tend to think of them, are: extremely tall stature, long limbs and strikingly long arm span, facial acne, mild mental retardation, severe mental illness (including psychosis) and aggressive, antisocial behavior with a long history of arrests, frequently beginning at an early age.
    On reading newspaper accounts of Richard Speck, who murdered eight Chicago student nurses in 1966, we noted all these traits and therefore concluded that Speck was a likely candidate for the XYY disorder. Independently, a cytogenetic laboratory in Chicago confirmed this hunch, reinforcing our inclination to believe that the XYY syndrome is really coming of age. It seems quite possible that in the XYY male, exemplified by Speck, biologists are describing in genetic terms a certain type of defective criminal who has long been explicitly recognized by the forensic psychiatrist.
  35. Daniel Hugon, Paris, France
  36. Lawrence Hannell, Melbourne, Australia
  37. Lyons, Richard D.. "Genetic abnormality is linked to crime; Genetics linked to violent crimes", April 21, 1968, p. 1. 
    • Lyons, Richard D.. "Ultimate Speck appeal may cite a genetic defect", April 22, 1968, p. 43. 
    • Lyons, Richard D.. "Chromosome test for flaws costly; 2 scientists cite scarcity of skilled aides for analyses", April 23, 1968, p. 27. 
    • editorial. "Nature or nurture?", April 23, 1968, p. 46. 
    • .. "Geneticist: Didn't test Speck", April 23, 1968, p. 8. 
      Dr. Pergament said he and Dr. Sato, a research fellow, had absolutely no connection with the Speck case and never examined Speck. The report was also denied by Speck's attorney, Public Defender Gerald W. Getty. "I never knew those doctors existed before I read about them in the paper," Getty said. Getty did say that a chromosomal test was performed on Speck, before Speck's trial, by a geneticist from outside the Chicago area. He declined to identify the geneticist, and he said the results of the test never have been disclosed. "It was agreed," he said, "that the results would not be disclosed unless I wished them disclosed. And I still don't." In any case, Getty said, the results could not be used in an appeal—since they were not part of the trial evidence. If anything, he said, they could only be used in connection with a new trial.
    • .. "Getty tells Speck case plea basis; 10 issues are raised regarding trial", November 26, 1968, p. A16. 
      At the same time he made public reports from Vanderbilt University showing no abnormal makeup of Speck's chromosomes...
      Getty displayed a letter of Sept. 26, 1966, relating that photographic evidence of 18 cells from Speck's blood showed no chromosome abnormality. He also exhibited a letter of last July 3, indicating that 100 of 101 cells in a sample of Speck's blood studied after the original tests showed the normal 46 chromosomes. The other cell had 45, regarded by the Vanderbilt investigators as having no significance.
    • Engel, Eric (September 1972). "The making of an XYY". Am J Ment Defic 77 (2): 123–7. PMID 5081078.—article by Vanderbilt University endocrinologist and geneticist Eric Engel, who performed two confidential chromosome analyses of Speck in September 1966 and June 1968. Based on mischaracterizations of XYY males as aggressive and violent criminals in the December 1965 and March 1966 preliminary reports by Jacobs, et al., Engel had made an unsolicited request in August 1966 to Speck's appointed defense attorney, Cook County Public Defender Gerald W. Getty, to confidentially karyotype Speck—which was repeated after false news reports in April 1968 that Speck was XYY.
  38. . (May 3, 1968). "Of chromosomes & crime". Time 91 (18): 41.
    • . (May 6, 1968). "Born bad?". Newsweek 76 (19): 87.
  39. Stock, Robert W.. "The XYY and the criminal", October 20, 1968, p. SM30. 
  40. The first XYY review article, by W. Michael Court Brown, a physician and world authority on radiation biology and cytogenetics, was published in December 1968, the month he died at age 50. Court Brown had established the MRC Clinical Effects of Radiation Unit at Western General Hospital in Edinburgh in 1956, which was renamed the MRC Clinical and Population Cytogenetics Unit in 1967 (and subsequently renamed the MRC Human Genetics Unit in 1988). In 1962, Court Brown had been the first to suggest—based on findings of antisocial behavior in some institutionalized Klinefelter's syndrome (47,XXY) patients and psychosis in some institutionalized Triple X syndrome (47,XXX) patients—that individuals with sex chromosome abnormalities could be held in law to suffer from diminished responsibility.
  41. Associated Press. "A kind word said for the XYY men; Psychiatrist cites evidence many are good citizens", May 6, 1969, p. 93. 
  42. Shah, Saleem A. (1970). Report on the XYY chromosomal abnormality, Public Health Service publication No. 2103. Chevy Chase, Md.: NIMH Center for Studies of Crime and Delinquency. OCLC 235264.  June 19–20, 1969 XYY conference.
  43. Associated Press. "Gene abnormality set for Md. study", December 27, 1969, p. B7. 
    • Bauer, Diane. "Maryland tests for criminal potential", January 22, 1970, p. 7.  reprinted in Katz (1972). Experimentation with human beings, pp. 342–343.
    • Cohen, Richard M.. "Genetic study is opposed", February 7, 1970, p. B2. 
    • Bauer, Diane. "XYY tests stop", February 13, 1970, p. 5.  reprinted in Katz (1972). Experimentation with human beings, pp. 343–344.
    • Bauer, Diane. "Criminal-prone tests resumed", May 4, 1970, p. 1.  reprinted in Katz (1972). Experimentation with human beings, p. 344.
    • . (May 18, 1970). "Congenital criminals?" 75 (20): 98–99.
    • Katz, Jay; Capron, Alexander Morgan; Glass, Eleanor Swift (1972). Experimentation with human beings; the authority of the investigator, subject, professions, and state in the human experimentation process. New York: Russell Sage Foundation, 342–346. ISBN 0871544385. 
    • Borgaonkar, Diagamber S.;Shah, Saleem A. (1974). "The XYY chromosome male—or syndrome?", Progress in medical genetics. Volume 10. New York: Grune & Stratton, 135–222. ISBN 0808908413. 
    • Borgaonkar, Diagamber S. (1978). "Cytogenic screening of community-dwelling males", Genetic issues in public health and medicine. Springfield, Ill.: Charles C Thomas, 215–234. ISBN 0398036594. 
    • Washington, Harriet A. (2004). "Born for evil? Stereotyping the karyotype: A case history in the genetics of aggressiveness", in Roelcke, Volker; Maio, Giovanni (eds.): Twentieth century ethics of human subjects research : historical perspectives on values, practices, and regulations. Stuttgart: Franz Steiner Verlag, 319–334. ISBN 351508455X. 
    • Washington, Harriet A. (2006). "The children's crusade: research targets young African Americans", Medical apartheid : the dark history of experimentation on black Americans from colonial times to the present. New York: Doubleday, 279–283. ISBN 0385509936. 
  44. Money, John; Wiedeking, Claus; Walker, Paul; Migeon, Claude; Meyer, Walter; Borgaonkar, Digamber (1975). "47,XYY and 46,XY males with antisocial and/or sex-offending behavior: antiandrogen therapy plus counseling". Psychoneuroendocrinology 1 (2): 165–176. PMID 1234655.—two other XYY boys (age 10) were deemed too young for chemical castration.
    • Wiedeking, Claus; Money, John; Walker, Paul (May 1979). "Follow-up of 11 XYY males with impulsive and/or sex-offending behaviour". Psychol Med 9 (2): 287–292. PMID 472074.
  45. Zech, Lore (December 1969). "Investigation of metaphase chromosomes with DNA-binding flurochromes". Exp Cell Res 58 (2–3).
  46. Pearson, Peter L.; Bobrow, Martin; Vosa, Canio G. (April 4, 1970). "Technique for identifying Y chromosomes in human interphase nuclei". Nature 226 (5240): 78–80. doi:10.1038/226078a0. PMID 4190810.
  47. Royce, Kenneth (June 1, 1970). The XYY Man. London: Hodder & Stoughton. ISBN 0340106948. 
    • Kneeland, Harold. "Books: Antiheroes and villians", December 8, 1970, p. B6. 
      The genetic fable is The XYY Man by Kenneth Royce (David McKay, $4.95). It leans so lightly on the theory that an extra Y chromosome produces a criminal that the reader can forget the biology and enjoy the fast footwork. Royce has simply manufactured a super cat burglar who is euchered into working for MI6. This tall (that chromosome), intelligent (that chromosome again), functionally nonviolent (that chromosome still again) fellow plays the damndest game with British internal security that ever filled a dossier...
  48. Fulton, Roger; Betancourt, John (1998). "Doomwatch", The Sci-Fi Channel encyclopedia of TV science fiction. New York: Aspect, 170. ISBN 0446674788.  By the Pricking of My Thumbs ... written by Robin Chapman. Sixteen-year-old Stephen Franklin is expelled from school because, his father says, he has an obscure genetic defect—an extra "Y" chromosome.
  49. Roush, Matt. "Critic's corner", November 17, 1993, p. 12D.  One of TV's most consistently rewarding series takes a grim and unforgettable detour into the bleak mindset of a teen-age sociopathic murderer. Is society to blame, or as his lawyer argues, is he genetically predisposed to violence, with an extra "Y" chromosome? … the boy's hopeless future seems all too evident.
  50. Hochman, David (May 7–13, 2007). "Horatio hunts a natural-born killer". TV Guide 55 (19): 34–36. There's nothing funny about the season finale. That episode is about a serial killer with "criminal" genes. "It's a real-life natural-born killer situation," executive producer Ann Donahue says. "Usually girls have XX chromosomes and boys have XY, but this kller is XYY, which means too much testosterone." Among other niceties, the killer who has ties to Boston … brands his female victims with the letter Y.
  51. Kovach, Bill. "Final approval of abortion bill voted in Albany; Rockefeller to sign it over weekend despite appeal by Cooke for veto", April 11, 1970, p. 1. 
  52. Sullivan, Walter. "Growth to slow down, association head says", December 29, 1970, p. 14. 
  53. Otto, James Howard; Towle, Albert (1973). Modern biology. New York: Holt, Rinehart and Winston, 185. ISBN 0030913373.  Another abnormal condition results when a normal X-bearing egg is fertilized by a YY sperm, formed by non-disjunction during spermatogenesis. This produces an XYY male who is usually over six feet in height and very aggressive.
  54. Freedman, Alfred M.; Kaplan, Harold I.; Sadock, Benjamin J. (1972). Modern Synopsis of Comprehensive Textbook of Psychiatry, 1st, Baltimore: Williams & Wilkins, 711. OCLC 1232929. â€œFigure 43.2” 
    • Sadock, Benjamin James; Sadock, Virginia Alcott (2007). Kaplan and Sadock's Synopsis of Psychiatry : Behavioral Sciences/Clinical Psychiatry, 10th, Philadelphia: Lippincott Williams & Wilkins, 154. ISBN 0-7817-7327-X.  A famous case of an "XYY" insanity defense is illustrated in Figure 4.4–1. Figure 4.4–1 Richard Speck. He was convicted in 1966 of slaying eight nurses in Chicago by stabbing and strangulation. His legal defense was based on his genetic makeup, which was "XYY." Individuals with these genes have been reported to be tall, mentally retarded, have acne, and show aggressive behavior... (Courtesy of Wide World Photos.)
  55. 55.0 55.1 Robinson, Arthur; Lubs, Herbert A.; Bergsma, Daniel (eds.) (1979). Sex chromosome aneuploidy: prospective studies on children, Birth defects original article series 15 (1). New York: Alan R. Liss. ISBN 0845110241. 
    • Stewart, Donald A. (ed.) (1982). Children with sex chromosome aneuploidy: follow-up studies, Birth defects original article series 18 (4). New York: Alan R. Liss. ISBN 0845110527. 
    • Ratcliffe, Shirley G.; Paul, Natalie (eds.) (1986). Prospective studies on children with sex chromosome aneuploidy, Birth defects original article series 22 (3). New York: Alan R. Liss. ISBN 0845110624. 
    • Evans, Jane A.; Hamerton, John L.; Robinson, Arthur (eds.) (1991). Children and young adults with sex chromosome aneuploidy: follow-up, clinical and molecular studies, Birth defects original article series 26 (4). New York: Wiley-Liss. ISBN 0471568465. 
  56. 56.0 56.1 56.2 Beckwith, Jon; King, Jonathan (November 1974). "The XYY syndrome: a dangerous myth". New Scientist 64 (923): 474–476. PMID 11664346.
  57. Witkin, Herman A.; et al. (August 13, 1976). "Criminality in XYY and XXY men". Science 193 (4253): 547–555. doi:10.1126/science.959813. PMID 959813.
  58. The five March of Dimes international conferences and four books also included reports on the findings of longitudinal prospective studies in London, Ontario and Tokyo on the development of children and with sex chromosome abnormalities identified in part by newborn screening programs.
  59. The last active longitudinal prospective study ended in 2000 with the end of the 36-year Denver study following the death of pediatrician and geneticist Arthur Robinson.
    • Robinson, Arthur; Linden, Mary G.; Bender, Bruce G. (1998). "Prenatal diagnosis of sex chromosome abnormalities", in Milunsky, Aubrey (ed.): Genetic disorders and the fetus : diagnosis, prevention and treatment, 4th, Baltimore: Johns Hopkins University Press, 249–285. ISBN 0801858011. 
    • (May/June 2001) "Life adaptation in 35 adults with sex chromosome abnormalities". Genet Med 3 (3): 187–191. PMID 11388759.
  60. Rao, Ercole; et al. (May 1997). "Pseudoautosomal deletions encompassing a novel homeobox gene cause growth failure in idiopathic short stature and Turner syndrome". Nat Genet 16 (1): 54–63. doi:10.1038/ng0597-54. PMID 9140395.
  61. </ol>

External links

  • Guy's Hospital Clinical Genetics Department (2001, 2005). The XYY condition. Scottish Genetics Education Network (ScotGEN)
    • XYY information leaflet based on work of Dr. Ratcliffe, a pediatrician and geneticist who led the largest of 7 international newborn screening studies of sex chromosome abnormalities.
  • Nielsen, Johannes (1998). XYY males. An orientation. The Turner Center, Aarhus Psychiatric Hospital, Risskov, Denmark.
    • XYY information booklet by Dr. Nielsen, a psychiatrist and geneticist who led the longest running of 7 international newborn screening studies of sex chromosome abnormalities.
  • Unique (http://www.rarechromo.org)
    • has XYY information leaflets available to members and available for purchase to non-members
  • Klinefelter Syndrome & Associates (http://www.genetic.org)
    • has 2006 Trisomy X and XYY National Conference binders and DVDs available for purchase
  • XYY syndrome page on the Contact a Family Directory website
    • has background and medical information and details of UK support groups


*Some information provided in whole or in part by http://en.wikipedia.org/