Pseudodicentric 22;Y translocation transmitted through four generations of a large family without phenotypic repercussion.

The most frequent Y-autosome translocations involve an acrocentric autosome and they are frequently familial with neither phenotypic nor reproductive repercussion. However, different Y-autosome translocations have been related to infertility, due to abnormal pairing of the X and Y chromosomes at meiosis and an abnormal XY-body formation or by the disruption of the AZFs (Azoospermic Factor). Rare forms of Y-autosome translocations are those resulting in an unbalanced 45-chromosome karyotype that includes a dicentric Y+autosome chromosome. We describe a new case of a familial pseudodicentric 22;Y that is carried by 19 male members of a large family without phenotypic repercussion. Cytogenetic analysis, fluorescence in situ hybridisation (FISH) and subtelomeric Multiplex Ligation-dependent Probe Amplification (MLPA) assay have been performed. All male members of the family showed the karyotype 45,X,psu dic(22;Y)(p11.2;qter).ish psu dic(22;Y) (SRY+,DYZ3+,D14/D22Z1+). In conclusion, the presence of the dicentric chromosome in the male members of the family reported does not seem to interfere with the correct progression of spermatogenesis. Copyright 2007 S. Karger AG, Basel.