Identification of A Novel Homozygous Mutation in Bbs10 Gene in An Iranianfamily With Bardet-Biedl Syndrome

Background: bardet–biedl syndrome (bbs) is a rare pleiotropic autosomal recessivedisease related to ciliopathies with approximately 25 causative genes. bbs is a multisystemicdisorder with wide spectrum of manifestations including truncal obesity, retinaldystrophy, male hypogenitalism, postaxial polydactyly, learning difficulties, andrenal abnormalities.methods: a consanguineous iranian family with a 28-year-old daughter affected withbbs, resulting from a first cousin marriage, was examined. after clinical examination,whole exome sequencing (wes) was applied. following the analysis of exome data,sanger sequencing was used to confirm as well as to co-segregate the candidate variantwith the phenotype.results: a novel homozygous variant [c. 2035g>a (p.e679k)] in exon 2 of the bbs10gene was found which was categorized as likely pathogenic based on american collegeof medical genetics and genomics (acmg) guidelines and criteria. in this study,the variant was fully co-segregated with the phenotype in the family.conclusion: despite overlapping with other ciliopathies in terms of the phenotype, thebbs has high genetic heterogeneity and clinical variability even among affectedmembers of a family. the symptoms observed in patients are largely related to thegenes involved and the type of mutations in the bbs. in this study, in addition to phenotypedescription of the proband harboring a novel disease-causing variant in bbs10gene, the spectrum of bbs symptoms was expanded. the findings of this study can beuseful in genetic counseling, especially for risk estimation and prenatal diagnosis.