Phenotype/karyotype correlations of Y chromosome aneuploidy with emphasis on structural aberrations in postnatally diagnosed cases
- New York Univ. School of Medicine, New York, NY (United States)
Over 600 cases with Y aneuploidy (other than non-mosaic 47,XYY) were reviewed for phenotype/karyotype correlations. Except for 93 prenatally diagnosed cases of mosaicism, all other cases were ascertained postnatally. Special emphasis was placed on structural abnormalities. It is clear that in the absence of a 45,X cell line, the presence of an entire Yp or a region of it including SRY would lead to a male phenotype in an individual with a Y aneuploidy, whereas the lack of Yp invariably leads to a female phenotype with typical or atypical Ullrich-Turner syndrome (UTS). Once there is a 45,X cell line, regardless of whether there is a Yp, Yq, or both Yp and Yq, or even a free Y chromosome in other cell lines, there is an increased chance for that individual to be a phenotypic female with UTS manifestations or to have ambiguous external genitalia. This review once again shows a major difference in reported phenotypes between postnatally and prenatally diagnosed cases of 45,X/46,XY, 45,X/47,XYY, and 45,X/46,XY/47,XYY mosaicism. It appears that ascertainment bias can explain the fact that all known patients with postnatal diagnosis are phenotypically abnormal, while over 90% of prenatally diagnosed cases are reported to have a normal male phenotype. Further elucidation of major Y genes and their clinical significance can be expected in the rapidly expanding gene mapping projects. More, consequently better, phenotype/karyotype correlations can be anticipated at both the cytogenetic and the molecular level. 486 refs., 5 figs., 10 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 61984
- Journal Information:
- American Journal of Medical Genetics, Vol. 53, Issue 2; Other Information: PBD: 1 Nov 1994
- Country of Publication:
- United States
- Language:
- English
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