Molecular cytogenetic characterization of a familial pericentric inversion 3 associated with short stature

Abstract

Short stature refers to the height of an individual which is below expected. The causes are heterogenous and influenced by several genetic and environmental factors. Chromosomal abnormalities are a major cause of diseases and cytogenetic mapping is one of the powerful tools for the identification of novel disease genes. Here we report a three generation family with a heterozygous pericentric inversion of 46, XX, inv(3) (p24.1q26.1) associated with Short stature. Positional cloning strategy was used to physically map the breakpoint regions by Fluorescence in situ hybridization (FISH). Fine mapping was performed with Bacterial Artificial Chromosome (BAC) clones spanning the breakpoint regions. In order to further characterize the breakpoint regions extensive molecular mapping was carried out with the breakpoint spanning BACs which narrowed down the breakpoint region to 2.9 kb and 5.3 kb regions on p and q arm respectively. Although these breakpoints did not disrupt any validated genes, we had identified a novel putative gene in the vicinity of 3q26.1 breakpoint region by in silico analysis. Trying to find the presence of any transcripts of this putative gene we analyzed human total RNA by RT-PCR and identified transcripts containing three new exons confirming the existence of a so far unknown gene close to the 3q breakpoint.