Fetal Loss: A Genetic Insight of the De Novo Accessory Bi-Satellited Marker of Chromosome 22P

Supernumerary Marker Chromosomes (SMC) follow non mendelian fashion in their inheritance, and are reported in variety of phenotypes. Although markers that contain satellites/bi-satellite variations of short arms do not confer any phenotypic alterations, it affects the fertility, vigour and interferes at non-disjunction during cell division and proves lethal to foetus. We report a couple wherein wife had Recurrent Early Pregnancy Loss (REPL) due to loss of fetal cardiac activity and husband with oligoasthenospermia. The cytogenetic analysis of the wife showed 46,XX,9qh+ karyotype and that of husband revealed 47,XY,+mar karyotype. Delineation of marker was initiated using NOR (Nucleolar Organizer Region), C-banding conventional techniques in combination with Fluorescence In Situ Hybridization (FISH) using Whole Chromosome (WCP) and Locus Specific Identifier (LSI) probes. Marker was characterized to be of chromosome 22 origin with satellites on either side of the centromere inferring it to be a bi-satellited iso-chromosome 22p with its occurrence as partial tetrasomy. Our study attempts to provide a comprehensive understanding of this cytogenetic rearrangement and its possible consequences in fertility and REPL.