rs771136797
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong
The NM_152618.3(BBS12):c.1198G>A(p.Val400Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000737 in 1,614,144 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V400V) has been classified as Benign.
Frequency
Consequence
NM_152618.3 missense
Scores
Clinical Significance
Conservation
Publications
- Bardet-Biedl syndrome 12Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Ambry Genetics, Myriad Women’s Health
- ciliopathyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- Bardet-Biedl syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| BBS12 | NM_152618.3 | c.1198G>A | p.Val400Met | missense_variant | Exon 2 of 2 | ENST00000314218.8 | NP_689831.2 | |
| BBS12 | NM_001178007.2 | c.1198G>A | p.Val400Met | missense_variant | Exon 3 of 3 | NP_001171478.1 | ||
| BBS12 | XM_011531680.3 | c.1198G>A | p.Val400Met | missense_variant | Exon 2 of 2 | XP_011529982.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000460 AC: 7AN: 152254Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000756 AC: 19AN: 251452 AF XY: 0.0000883 show subpopulations
GnomAD4 exome AF: 0.0000766 AC: 112AN: 1461890Hom.: 0 Cov.: 69 AF XY: 0.0000853 AC XY: 62AN XY: 727246 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000460 AC: 7AN: 152254Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74390 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Bardet-Biedl syndrome 12 Uncertain:5
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
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This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
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not specified Uncertain:1
Variant summary: BBS12 c.1198G>A (p.Val400Met) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 7.6e-05 in 251452 control chromosomes (gnomAD). This frequency is not higher than expected for a pathogenic variant in BBS12 causing Bardet-Biedl Syndrome (7.6e-05 vs 0.00076), allowing no conclusion about variant significance. c.1198G>A has been reported in the literature in an individual affected with Bardet-Biedl Syndrome who carried the variant in the homozygous state in cis with a different potentially pathogenic variant (Billingsley_2010). This report does not provide unequivocal conclusions about association of the variant with Bardet-Biedl Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS. -
BBS12-related disorder Uncertain:1
The BBS12 c.1198G>A variant is predicted to result in the amino acid substitution p.Val400Met. This variant was reported in the homozygous state in two siblings with Bardet-Biedl syndrome (Billingsley et al 2010. PubMed ID: 20472660). However, an additional homozygous variant in BBS12 as well as a single missense variant in BBS1 were also found in these siblings. This variant is reported in 0.099% of alleles in individuals of Ashkenazi Jewish descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
not provided Uncertain:1
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Bardet-Biedl syndrome Uncertain:1
This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 400 of the BBS12 protein (p.Val400Met). This variant is present in population databases (rs771136797, gnomAD 0.1%). This missense change has been observed in individual(s) with Bardet-Biedl syndrome (PMID: 20472660). ClinVar contains an entry for this variant (Variation ID: 281597). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at