PRESENCE OF Y-CHROMOSOME SEQUENCES AND THEIR EFFECT ON THE PHENOTYPE OF 6 PATIENTS WITH Y-CHROMOSOME ANOMALIES

The extent of Y chromosome material was determined in 6 southern Afric an subjects with sex chromosome anomalies. Four of the subjects were p henotypically female, and 2 were phenotypically male. Molecular and cy togenetic findings were correlated with phenotypic expression. An X;Y translocation was found in both male subjects, and in one female subje ct. The remaining female subjects were characterized by an isodicentri c Y, an isochromosome Yq, and a micromarker of undetermined origin, re spectively. The individuals were tested for the presence of a number o f Y-specific DNA sequences. Molecular findings were generally compatib le with the cytogenetic findings, and also with the phenotypic sex of the patients. All the female subjects had Y material and all but one w ere negative for the sex determining region of the Y (SRY). The somati c Ullrich-Turner-like findings present in 3 of the females were attrib uted to either the presence of a 45,X cell line and/or a single copy o f Xp. The males both showed X;Y translocations without any detectable loss of Y DNA. Although molecularly very similar, the disparate clinic al findings in these 2 subjects could have been accounted for by diffe rent X inactivation patterns. (C) 1995 Wiley-Liss, Inc.