ORPHA: 110; DO: 0110135;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 17q22 | Bardet-Biedl syndrome 13 | 615990 | Autosomal recessive | 3 | MKS1 | 609883 |
A number sign (#) is used with this entry because of evidence that Bardet-Biedl syndrome-13 (BBS13) is caused by compound heterozygous mutation in the MKS1 gene (609883) on chromosome 17q22.
BBS13 is an autosomal recessive ciliopathy with features of obesity, polydactyly, and retinitis pigmentosa (Leitch et al., 2008; Xing et al., 2014).
For a general phenotypic description and a discussion of genetic heterogeneity of Bardet-Biedl syndrome, see BBS1 (209900).
Xing et al. (2014) reported a Chinese boy with BBS13. Although clinical details were not provided, the child was noted to have typical symptoms, such as retinitis pigmentosa, obesity, and polydactyly. Ophthalmologic examination showed bone-spicule hyperpigmentation and attenuated arteries.
In a 2-year-old patient of Turkish descent with Bardet-Biedl syndrome, Leitch et al. (2008) identified compound heterozygosity for mutations in the MKS1 gene: a missense mutation (C492W; 609883.0006) and a 3-bp in-frame deletion resulting in deletion of phenylalanine (F371del; 609883.0007). Functional studies in zebrafish demonstrated that the missense mutation results in a hypomorphic allele and the deletion in a functionally null allele. The authors also detected heterozygous mutations in MKS1 in 5 families; 2 of these families also carried mutations in BBS10 (610148), 1 in heterozygosity and 1 in homozygosity, and a third family carried a homozygous mutation in BBS1 (209901). Leitch et al. (2008) concluded that their data extended the genetic stratification of ciliopathies and suggested that BBS and Meckel syndrome (see 609883), although distinct clinically, are allelic forms of the same molecular spectrum.
In a Chinese boy with BBS13, Xing et al. (2014) identified compound heterozygous missense mutations in the MKS1 gene (Y461C, 609883.0008; and R534Q, 609883.0009). The mutations were identified by high-throughput targeted exome sequencing of 144 known genes responsible for inherited retinal diseases. Functional studies of the variants were not performed.
Leitch, C. C., Zaghloul, N. A., Davis, E. E., Stoetzel, C., Diaz-Font, A., Rix, S., Alfadhel, M., Lewis, R. A., Eyaid, W., Banin, E., Dollfus, H., Beales, P. L., Badano, J. L., Katsanis, N. Hypomorphic mutations in syndromic encephalocele genes are associated with Bardet-Biedl syndrome. Nature Genet. 40: 443-448, 2008. Note: Erratum: Nature Genet. 40: 927 only, 2008. [PubMed: 18327255] [Full Text: https://doi.org/10.1038/ng.97]
Xing, D.-J., Zhang, H.-X., Huang, N., Wu, K.-C., Huang, X.-F., Huang, F., Tong, Y., Pang, C.-P., Qu, J., Jin, Z.-B. Comprehensive molecular diagnosis of Bardet-Biedl syndrome by high-throughput targeted exome sequencing. PLoS One 9: e90599, 2014. Note: Electronic Article. [PubMed: 24608809] [Full Text: https://doi.org/10.1371/journal.pone.0090599]