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.
BBS1 mutations and the clinical impact
BBS1 gene is one of the 26 genes whose changes (mutations) can cause BBS.
It is located on the long arm of chromosome 11.
BBS can be caused by two identical (homozygous mutations) or two different mutations from each parent (compound heterozygous mutations) in this gene. The most common mutation, accounting for 50% of BBS1 cases, replaces a methionine with an arginine at protein position 390 (Met390Arg).
The BBS1 protein, encoded by the BBS1 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.
BBS1