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

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000077 ( 0 hom. )

Consequence

BBS12
NM_152618.3 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: 0.722

Publications

3 publications found
Variant links:
Genes affected
BBS12 (HGNC:26648): (Bardet-Biedl syndrome 12) The protein encoded by this gene is part of a complex that is involved in membrane trafficking. The encoded protein is a molecular chaperone that aids in protein folding upon ATP hydrolysis. This protein also plays a role in adipocyte differentiation. Defects in this gene are a cause of Bardet-Biedl syndrome type 12. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, May 2010]
BBS12 Gene-Disease associations (from GenCC):
  • Bardet-Biedl syndrome 12
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Ambry Genetics, Myriad Women’s Health
  • ciliopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Bardet-Biedl syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.053281218).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BBS12NM_152618.3 linkc.1198G>A p.Val400Met missense_variant Exon 2 of 2 ENST00000314218.8 NP_689831.2
BBS12NM_001178007.2 linkc.1198G>A p.Val400Met missense_variant Exon 3 of 3 NP_001171478.1
BBS12XM_011531680.3 linkc.1198G>A p.Val400Met missense_variant Exon 2 of 2 XP_011529982.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BBS12ENST00000314218.8 linkc.1198G>A p.Val400Met missense_variant Exon 2 of 2 1 NM_152618.3 ENSP00000319062.3
BBS12ENST00000542236.5 linkc.1198G>A p.Val400Met missense_variant Exon 3 of 3 2 ENSP00000438273.1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152254
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00144
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000756
AC:
19
AN:
251452
AF XY:
0.0000883
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000992
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000766
AC:
112
AN:
1461890
Hom.:
0
Cov.:
69
AF XY:
0.0000853
AC XY:
62
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.000918
AC:
24
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.000104
AC:
9
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000603
AC:
67
AN:
1112010
Other (OTH)
AF:
0.000116
AC:
7
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
8
16
23
31
39
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000460
AC:
7
AN:
152254
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74390
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41464
American (AMR)
AF:
0.0000654
AC:
1
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00144
AC:
5
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000118
Hom.:
1
Bravo
AF:
0.0000340
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.000218
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Bardet-Biedl syndrome 12 Uncertain:5
Jan 19, 2017
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

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. -

May 18, 2021
Pars Genome Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. -

Jan 08, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 28, 2021
New York Genome Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Feb 18, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Feb 08, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

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
Jun 18, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Bardet-Biedl syndrome Uncertain:1
Jul 31, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Benign
-0.084
T
BayesDel_noAF
Benign
-0.12
CADD
Benign
5.9
DANN
Uncertain
0.99
DEOGEN2
Benign
0.15
T;T
Eigen
Benign
-1.0
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.20
N
LIST_S2
Benign
0.67
T;.
M_CAP
Benign
0.049
D
MetaRNN
Benign
0.053
T;T
MetaSVM
Benign
-0.88
T
MutationAssessor
Uncertain
2.6
M;M
PhyloP100
0.72
PrimateAI
Benign
0.35
T
PROVEAN
Benign
-1.3
N;N
REVEL
Uncertain
0.48
Sift
Benign
0.17
T;T
Sift4G
Benign
0.15
T;T
Polyphen
0.34
B;B
Vest4
0.048
MutPred
0.49
Gain of disorder (P = 0.1294);Gain of disorder (P = 0.1294);
MVP
0.92
MPC
0.38
ClinPred
0.051
T
GERP RS
1.9
Varity_R
0.038
gMVP
0.43
Mutation Taster
=31/69
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs771136797; hg19: chr4-123664245; COSMIC: COSV58562461; COSMIC: COSV58562461; API