About Cryptic Acrocentric Pericentromeric Abnormalities in Infertile

Abstract

Cryptic balanced chromosomal aberrations can be an underlying cause of infertility. In 2003 Cockwell and coworkers highlighted the relevance of euchromatic pericentric regions of acrocentric chromosomes that may be a yet ignored genomic region hosting cryptic rearrangements. Here we offer the first follow-up study to further explore this idea. Two specific molecular cytogenetic probe sets were established to elucidate such cryptic rearrangements together with chromosomal heteromorphisms of acrocentric centromeres. In 28 infertile couples and 20 controls, the rate of centromeric heteromorphisms was almost comparable in both groups and one heteromorphism was noted in ~30% of the cases, and two heteromorphisms in ~15% and three heteromorphisms 5%. However, none of the studied groups revealed any cryptic euchromatic pericentromeric abnormalities of the acrocentrics. Nonetheless, in parallel an infertile case with an inv(13)(p12q12.1?2) was uncovered, being not part of the systematically studied group of infertile. As unbalanced products of meiosis with such or similar karyotypes can potentially contribute to abortions, the existence of rare, cryptic pericentromeric euchromatic abnormalities in the acrocentrics thus needs to be still expected in banding cytogenetic diagnostics. Accordingly, this study reflected that suspicious acrocentric short arms in infertile need special attention and further characterization by fluorescence in situ hybridization.