XYY Syndrome

Abstract

XYY syndrome is a genetic condition in which males have 47 chromosomes instead of the usual 46 chromosomes. The karyotype is written as 47,XYY as these males have an extra Y chromosome. XYY occurs in approximately one in 1000 live male births and falls into the category of sex chromosome aneuploidy. Males with XYY often have tall stature but otherwise are not significantly different in physical appearance compared to other men. They are generally healthy; however, some XYY men can have learning disabilities or behaviour problems. It is possible that the information we know about XYY syndrome in the medical literature may be biased, as healthy, developmentally normal males do not often have a reason to have a karyotype performed. We may overestimate some of the problems associated with XYY such as learning disabilities and behaviour problems, as these are common reasons for children to have a karyotype.

Key Concepts:

  • Males with XYY syndrome have 47 chromosomes, which includes an extra Y chromosome.

  • Males with XYY syndrome appear physically normal, however often have tall stature.

  • Males with XYY syndrome generally have normal intelligence, however some may have learning disabilities or behaviour issues.

  • Males with XYY syndrome do not have criminal tendencies as suggested in the older literature.

Keywords: XYY; aneuploidy; sex chromosome; tall stature; learning disability; attention deficit hyperactivity disorder

Figure 1.

In XYY, the karyotype (chromosome count) is 47,XYY. This means that each of the somatic cells contains 47 chromosomes, 22 normal pairs of autosomes, and three sex chromosomes, one X chromosome and two Y chromosomes. Figure Courtesy of A. J. Dawson.

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References

Austin GE and Sparkes RS (1980) Abnormal cerebral cortical convolutions in an XYY fetus. Human Genetics 56: 173–175.

Bishop DV, Jacobs PA, Lachlan K et al. (2011) Autism, language and communication in children with sex chromosome trisomies. Archives of Disease in Childhood 96(10): 954–959.

Boisen E and Rasmussen L (1978) Tremor in XYY and XXY men. Acta Neurologica Scandinavica 58: 66–73.

Daly R and Matthews C (1974) Impaired motor function in XYY males. Neurology 24: 655–658.

El‐Dahtory and Elsheikha (2009) Male infertility related to an aberrant karyotype, 47,XYY: four case reports. Cases Journal 2: 28.

Geerts M, Steyaert J and Fryns JP (2003) The XYY syndrome: a follow‐up study on 38 boys. Genetic Counselling 14: 267–279.

Gonzalez‐Merino E, Hans C, Abramowicz M, Englert Y and Emiliani S (2007) Aneuploidy study in sperm and preimplantation embryos from nonmosaic 47,XYY men. Fertility and Sterility 88(3): 600–606.

Hakola HP and Iivanainen M (1978) Pneumoencephalographic and clinical findings of the XYY syndrome. Acta Psychiatrica Scandinavica 68: 360–370.

Hofherr SE, Wiktor AE, Kipp BR, Dawson DB and Van Dyke DL (2011) Clinical diagnostic testing for the cytogenetic and molecular causes of male infertility: the Mayo clinic experience. Journal of Assisted Reproduction and Genetics 28(11): 1091–1098.

Jacobs PA, Brunton M, Melville MM, Brittain RP and McClemont WF (1965) Aggressive behaviour, mental sub‐normality and the XYY male. Nature 208: 1351–1352.

Jones KL (2006) Smith's Recognizable Patterns of Human Malformation, 6th edn. Philadelphia: Elsevier Saunders.

Linden MG and Blender BG (2002) Fifty‐one prenatally diagnosed children and adolescents with sex chromosome abnormalities. American Journal of Medical Genetics 10: 11–18.

Martin RH (2008) Cytogenetic determinants of male fertility. Human Reproduction 14: 379–390.

Martin RH, McInnes B and Rademaker AW (1999) Analysis of aneuploidy for chromosomes 13, 21, X and Y by multicolour fluorescence in situ hybridization (FISH) in a 47,XYY male. Zygote 7: 131–134.

Maymon R, Herman A and Reish O (2002) Brain anomalies associated with 47,CYY karyotypes detected on prenatal scan. Prenatal Diagnosis 22: 490–492.

Nicolson R, Bhalerao S and Sloman L (1998) 47,XYY karyotypes and pervasive developmental disorders. Canadian Journal of Psychiatry 43: 619–622.

Nielsen E and Wohlert E (1990) Sex chromosomes abnormalities found among 34,910 newborn children: results from a 13 year study in Arhus, Denmark. 19. In: Evans JA, Hamerton JL and Robinson A (eds) Children and Young Adults with Sex Chromosome Aneupolidy, vol. 26, pp. 209–223. New York: Wiley Liss.

Ratcliffe S (1999) Long‐term outcome in children of sex chromosome abnormalities. Archives of Disease in Childhood 80(2): 192–195.

Ross JL, Zeger MP, Kushner H, Zinn AR and Roeltgen DP (2009) An extra X or Y chromosome: contrasting the cognitive and motor phenotypes in childhood in boys with 47,XYY syndrome or 47,XXY Klinefelter syndrome. Developmental Disabilities Research Reviews 15(4): 309–317.

Stochholm K, Juul S and Gravholt CH (2010) Diagnosis and mortality in 47,XYY persons: a registry study. Orphanet Journal of Rare Diseases 5: 15.

Tartaglia NR, Ayari N, Hutaff‐Lee C and Boada R (2012) Attention‐deficit hyperactivity disorder symptoms in children and adolescents with sex chromosome aneuploidy: XXY, XXX, XYY and XXYY. Journal of Developmental & Behavioral Pediatrics 33(3): 1–10.

Torniero C, Bernardina BD, Fontana E et al. (2011) Electroclinical findings in four patients with karyotype 47,XYY. Brain Development 33(5): 384–389.

Warwick MM, Doody GA, Lawrie SM et al. (1999) Volumetric magnetic resonance imaging study of the brain in subjects with sex chromosome aneuploidies. Journal of Neurology, Neurosurgery, and Psychiatry 66: 628–632.

Further Reading

Rimoin DL, Connor JM and Pyeritz RE (2006) Emery and Rimoin's Principles and Practice of Medical Genetics, 5th edn. New York: Churchill Livingstone.

Web Links

National Organization for Rare Disorders (NORD) http://www.rarediseases.org/

Unique – Rare Chromosome Disorder Support Group http://www.rarechromo.org http://www.rarechromo.org/files/XYYStudyDayReport.pdf

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How to Cite close
Goobie, Sharan, and Prasad, Chitra(Jul 2012) XYY Syndrome. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0005157.pub2]