Mapping of Genes Involved in Bardet-Biedl Syndrome (BBS) in Pakistani Population

Bardet-Biedl Syndrome (BBS), one of an autosomal recessive or clinically and genetically heterogeneous disorder, which prevails all over the world and results due to increased rate of consanguinity. All of these BBS genes are involved either directly or indirectly in signaling pathways such as Leptin receptor signaling pathway and Wnt signaling pathway. The study presented here includes genetic mapping of two consanguineous families (A & B) with BBS. (21.63-Mb) region was found to be critical as it was gene rich and contains approximately eighty known and predicted genes. Out of eighty genes six (FGF2, BBS7, BBS12, NUDT6, SPATA5 and SPRY1) were found to be candidate genes. On mutations screening, sequencing of the coding exon 2 of BBS12 in affected individuals identified a novel homozygous c.2103C 1 A mutation, which is predicted to insert a stop codon at position 701 of the BBS12 protein (p.S701X). Identification of BBS12 mutation in families B can increase our understanding of molecular genetics and pathophysiology of BBS.