title: Alphoidless centromere of a familial unstable inverted Y chromosome.
abstract: We report on a 3-generation pedigree in which an inverted unstable Y chromosome had no phenotypical or reproductive repercussion despite a sizable 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 nonalphoid centromeric sequences.
authors.affiliation: División de Genética, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico.
authors.forename: H
authors.initials: H
authors.lastname: Rivera
authors.forename: A I
authors.initials: AI
authors.lastname: Vassquez
authors.forename: M L
authors.initials: ML
authors.lastname: Ayala-Madrigal
authors.forename: M L
authors.initials: ML
authors.lastname: Ramirez-Dueñas
authors.forename: I P
authors.initials: IP
authors.lastname: Davalos
mesh_terms: D000293:Adolescent; D000782:Aneuploidy; D002503:Centromere / Q000235:genetics*; D007446:Chromosome Inversion; D004276:DNA, Satellite; D006801:Humans; D008297:Male; D008938:Mitosis / Q000235:genetics; D010375:Pedigree; D011110:Polymorphism, Genetic; D014998:Y Chromosome
chemical_list: D004276:DNA, Satellite