Molecular cytogenetic characterization of three familial cases of satellited Y chromosomes.

Three families in which a satellited Y chromosome (Yqs) was segregating without apparent phenotypic effect were re-investigated with non-isotopic in situ hybridization methods. Active nucleolus organizer regions were seen in the distal long arm region of all Yqs chromosomes studied and in situ hybridization with the probe D15Z1 showed that, in all three families, the Yqs was the result of a 15p;Yq translocation. In one case, an additional focus of D15Z1 hybridization was seen on 21p.