ESPE Abstracts

Bardet-Biedl syndrome (BBS) is a rare and multisystemic disorder characterized by rod-cone dystrophy, post-axial polydactyly, learning difficulties, renal abnormalities, obesity and hypogonadism. The disorder is genetically heterogeneous. To date, 21 genes present on different chromosomes have been mapped. The most common genes are BBS1 (locus 11q13) and BBS10 (locus 12q21.2). We aimed to report two family with five affected children with typical clinical features of Bardet-Biedl Syndrome. The first family was Turkish, and the second family was Syrian. There were a consanguineous marriage in both family. There were two affected girls in the turkish family, and they were 14 and 17 years old, respectively. Two of the three affected children in the syrian family were boys and one was girls. their ages were 4, 7 and 10. All of the children had obesity, polydactyly and cognitive impairment. Rode-cone dystrophy and hepatic steatosis were more severe in Syrian families. they had no kidney disease. whereas both children had pelvicalyceal ectasia in the first family. In addition, there was pulmonary hypertension at the girl who is seventeen. Cognitive impairment was mild in all. Screening analysis was performed for BBS1, BBS2 and BBS10 genes. There were no changes that could be pathogenic in the BBS1 and BB2 genes.BBS10 gene 1-2. exons were amplified by PCR method and then DNA sequence analysis were done. We identified a novel homozygous mutation in exon 2 in BSS10 gene. The change in pThr516Asnfs*8 (c.1547 delC) detected in patients was not defined in HGMD. However, the mutation taster bioinformatics program predicts that change is the cause of the disease. This change also constitutes an early stop codon. It is thought to be pathogenic for this reason. Due to the rare and heterogeneous nature of BBS, the detection of specific and non-specific clinical findings, including ocular findings, obesity, cognitive impairment, should be considered BBS. Genetic testing is necessary to confirm the diagnosis.