A novel missense variant in the BBS7 gene underlying Bardet-Biedl syndrome in a consanguineous Pakistani family

Bardet-Biedl syndrome (BBS) is characterized by six major features: postaxial polydactyly, obesity, learning disabilities, renal anomalies, retinitis pigmentosa and hypogonadism and is inherited in an autosomal recessive manner. BBS is caused by disease causing sequence variants in the 22BBSgenes identified to date. In the present study, a single consanguineous Pakistani Family with BBS was clinically and genetically characterized. After establishing linkage to aBBSgene on chromosome 4q27, Sanger sequencing was performed in all available affected and unaffected members. Sequence analysis of theBBS7gene revealed novel substitution mutation (c.719G>T; p. Gly240Val). Our findings further extend the body of evidence implicating BBS7 in causing BBS and expand the mutation spectrum.