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 22 BBS genes identified to date. In the present study, a single consanguineous Pakistani Family with BBS was clinically and genetically characterized. After establishing linkage to a BBS gene on chromosome 4q27, Sanger sequencing was performed in all available affected and unaffected members. Sequence analysis of the BBS7 gene 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.