XYY 증후군

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XYY 증후군
Y 염색체
Y 염색체
ICD-10 Q98.5
ICD-9 758.8
질병DB 33038
MeSH D014997

XYY 증후군(영어: XYY syndrome)은 인간 남성Y 염색체가 하나 더 있어서 일반 46개의 염색체가 아닌 총 47개의 염색체가 있는 성 염색체 이수성 증후군이다. 야콥 증후군, 제이콥스 증후군으로도 불린다. 이 증후군은 47,XYY 핵형을 만들어내는데, 이는 1,000명의 출생 남아(男兒) 가운데 1명에게 발생한다.

의학적 표현형은 정상이고[1][2] 47,XYY 남성 중 대다수가 자신의 핵형을 알지 못하기 때문에[3], 일부 의학 유전학자들 사이에서는 이 용어를 증후군으로 부르는 것이 적절한지에 대한 논란이 있다.[1]

원인[편집]

XYY syndrome.svg

47,XYY는 유전되는 것은 아니지만, 일반적으로 정자 세포의 형성 기간 동안 무작위로 발생한다. 비분열(비분리)로 불리는, 감수 분열 2단계의 염색체 분리 오류가 발생하면 Y 염색체가 하나 더 생기는 정자 세포가 생산될 수 있다. 이 비정상적인 정자 세포들 가운데 하나가 아이의 유전적 구성에 기여하는 경우 아이는 몸 세포 각각에 Y 염색체가 하나 더 붙게 된다.[4]

초기 태아 단계의 접합자 이후 유사 분열 시기에 세포 분열을 하다가 비분열(비분리)이 일어나 Y 염색체가 하나 더 붙는 경우도 일부 있다. 이는 46,XY/47,XYY 모자이크가 생성될 수 있다.[4]

같이 보기[편집]

주석[편집]

  1. Graham, Gail E.; Allanson, Judith E.; Gerritsen, Jennifer A. (2007). 〈Sex chromosome abnormalities〉, 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, 1038–1057쪽. ISBN 0-443-06870-4 “This sex chromosome aneuploidy is not characterized by distinct physical features and, because there does not appear to be recognizable pattern of neurodevelopment or behavioral characteristics, the use of the term syndrome may be inappropriate. Males with an extra Y chromosome are phenotypically normal and most never come to medical attention.
    Pubertal development, testicular histology, and spermatogenesis are most often normal.
    It appears that XY pairing and recombination occur normally in 47,XYY, the extra Y chromosome being lost during spermatogenesis, so that many XYY men have fathered chromosomally normal children. It has generally been observed that reproductive risks for males with 47,XYY are no higher than for euploid males, despite the fact that in situ hybridization studies demonstrated a lower frequency of single Y-bearing sperm than expected and a variably higher rate of disomic XX, XY and YY spermatozoa in males with 47,XYY.
    Population-based studies have demonstrated that intellectual abilities tend to be slightly lower than those of siblings and matched controls and that boys with an extra Y chromosome are more likely to require educational help. However, intelligence is usually well within the normal range.
    During school age, learning disabilities requiring educational intervention are present in approximately 50% and are as responsive to therapy as they are in children with normal chromosomes. Expressive and receptive language delays and reading disorders are common.”
  2. Milunsky, Jeff M. (2010). 〈Prenatal diagnosis of sex chromosome abnormalities〉, Milunsky, Aubrey; Milunsky, Jeff M. (eds.): 《Genetic disorders and the fetus: diagnosis, prevention and treatment》, 6th, Oxford: Wiley-Blackwell, 273–312쪽. ISBN 1-4051-9087-6 “The addition of a Y chromosome to a normal male chromosome constitution does not produce a discernible phenotype. Males with 47,XYY cannot be characterized by discriminating physical or behavioral features. The first diagnosis of this condition, therefore, was a karyotypic and not a phenotypic discovery.
    Pubertal development is normal and these men are usually fertile.”
  3. Jacobs, Patricia A. (2006년 March 3–5,월). 《The discovery and history of Trisomy X and XYY syndrome》. Sacramento: KS&A
    Oxford Data Base — XYY total ascertainment: ~ 3% — 934 XYYs (801 XYYs + 133 XYY mosaics) in Britain (population 60 million)
  4. 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. PMID 10545600. doi:10.1093/hmg/8.12.2205.

바깥 고리[편집]

  • 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.
  • XYY syndrome page on the Contact a Family Directory website
    • has background and medical information and details of UK support groups