Alphoidless centromere of a familial unstable inverted Y chromosome
Rivera, H.; Vassquez, A.I.; Ayala-Madrigal, M.L.; Ramirez-Dueñas, M.L.; Davalos, I.P.
Annales de Genetique 39(4): 236-239
1996
ISSN/ISBN: 0003-3995 PMID: 9037351 Document Number: 465742
We report on a 3-generation pedigree in which an inverted unstable Y chromosome had no phenotypical or reproductive repercussion despite a sizeable proportion of secondary aneuploidies (mainly 45, X cells) in lymphocytes. This chromosome was metacentric and had a single Cd-positive primary constriction, but occasionally assumed a normal acrocentric aspect. FISH using the probe DYZ3 revealed a single strong signal; unexpectedly, the signal was outside the primary constriction and appeared to map in the middle of p, that is, at the usual centromeric localisation. Therefore, this chromosome should be regarded as a remarkable pseudodicentric because the major alphoid array was located at the inactive centromere but not at the active one. This chromosome may have resulted from a) a transcentric inversion with the 48 bp satellite array of proximal Yq being relocated next to the Yq heterochromatin, or b) an intrachromosomal insertion of nonalphold centromeric sequences.