Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate
The NM_031885.5(BBS2):c.1046T>G(p.Leu349Trp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000657 in 1,614,082 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
BBS2 (HGNC:967): (Bardet-Biedl syndrome 2) This gene is a member of the Bardet-Biedl syndrome (BBS) gene family. Bardet-Biedl syndrome is an autosomal recessive disorder characterized by severe pigmentary retinopathy, obesity, polydactyly, renal malformation and cognitive disability. The proteins encoded by BBS gene family members are structurally diverse and the similar phenotypes exhibited by mutations in BBS gene family members is likely due to their shared roles in cilia formation and function. Many BBS proteins localize to the basal bodies, ciliary axonemes, and pericentriolar regions of cells. BBS proteins may also be involved in intracellular trafficking via microtubule-related transport. The protein encoded by this gene forms a multiprotein BBSome complex with seven other BBS proteins.[provided by RefSeq, Oct 2014]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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BBS2-related disorder Uncertain:1
Feb 21, 2024
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing
The BBS2 c.1046T>G variant is predicted to result in the amino acid substitution p.Leu349Trp. This variant was reported in the heterozygous state in individuals with Bardet-Biedl syndrome; however, these individuals were also homozygous for a pathogenic variant in BBS1 (Beales et al. 2003. PubMed ID: 12677556; Badano et al. 2003. PubMed ID: 12837689). Functional studies in zebrafish suggest this variant may not impact protein function (Table S4/S5, Zaghloul et al. 2010. PubMed ID: 20498079). This variant is reported in 0.0039% of alleles in individuals of European (Non-Finnish) descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -