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 involv ing structurally abnormal Y chromosomes. Karyotypes were performed by stand ard cytogenetic methods and, in some cases, by fluorescence in situ hybridi zation, 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 t he Y chromosome in these instances is related to the site of the break poin t on Yq.