[Dicentric Yp chromosome as one of the reasons for the absence of fluorescence in human Y chromosome].

In chromosome sets of three patients with Turner's syndrome non-fluorescent Y-chromosomes of normal size were found in part of the cells. C-, Q- and G-techniques have shown that they were dicentric Yp-chromosomes, resulting from a junction of long arms of two Y-chromosomes with simultaneous loss of the entire distal fluorescent segments. It is supposed that in some cases the non-fluorescent Y-chromosomes, previously described in literature, are as a matter of fact undiscernible dicentric Yp-chromosomes.