Inheritance of Bardet-Biedl syndrome (BBS)
Bardet-Biedl syndrome is a genetic condition. The inheritance is autosomal recessive. This means that male and female are equally affected and that parents are usually asymptomatic carriers.
BBS10mutations and the clinical impact
BBS10gene is one of the 26 genes whose changes (mutations) can cause BBS. It is located on the long arm of chromosome 12. BBS can be caused by two identical (homozygous mutations) or two different mutations from each parent (compound heterozygous mutations) in this gene. One of the most common mutation in Northern Europe (p.C91Lfs*5) replaces the amino acid at position 91 from Cysteine to Leucine, and then causes a frameshift, which is a shift in the reading frame of the mRNA, resulting in a 5 amino acid deletion. This frameshift introduces a stop codon early, causing the protein to be truncated and non-functional.
The BBS10 protein, encoded by the BBS10 gene, is one of the proteins of the primary cilium (PC), a cellular organelle involved in several biological functions. The mechanism underlying the BBS is not fully understood but it is believed to be linked to PC dysfunction. The latter is a non-motile structure extruding from the surface of the cells. It is important in sensing external stimuli allowing communication between cells, cell division, polarity and metabolism.
Diagnostic testing
Bardet-Biedl syndrome can be diagnosed by suggestive clinical characteristics with genetic testing. The genetic testing can be by targeted single gene sequencing, multi-gene panels or whole exome sequencing.
BBS10