Molecular analysis of Y chromosome long arm structural instability in patients with gonadal dysfunction.

We have performed cytogenetic and molecular analyses of 45,X mosaics involving structurally abnormal Y chromosomes. Karyotypes were performed by standard cytogenetic methods and, in some cases, by fluorescence in situ hybridization, to distinguish monocentric and dicentric chromosomes. In addition, the deletions of Yq have been mapped using Southern blotting and polymerase chain reaction analysis. This paper provides additional information on the analysis of Y chromosome aberrations, and suggests that the stability of the Y chromosome in these instances is related to the site of the break point on Yq.