Abnormalities of human sex chromosomes. I. A ring Y without mosaicism Article

cited authors

  • German, J; Simpson, JL; McLemore, GA

fiu authors

abstract

  • Phenotypic karyotypic correlations in the case of a short man with a minute ring Y chromosome suggest, as have previously reported studies of other individuals with abnormal chromosomal complements, that genetic determinants for differentiation of the testis are situated very close to the centromere of the Y. This man's shortness probably resulted from loss of a segment of the Y chromosome that normally exerts a positive effect on body height, the segment possibly being genetically homologous with the one having a similar effect situated near the telomere of the short arm of the X chromosome. It is postulated that during evolution this segment which when hemizygous results in short stature, has been retained near the telomere of an arm of the X and an arm of the Y, with the result that: a degree of X-Y pairing and subsequent normal disjunction at metaphase I is ensured; and yet simultaneously, this terminal pairing segment is suitably and safely distanced from the segregated genetic determinants for testis differentiation, return of which to the X by crossing over would interfere with the perfection demanded of a mechanism selected to maintain two distinct sexes.

publication date

  • December 1, 1973

start page

  • 225

end page

  • 231

volume

  • 16

issue

  • 4