NM_031885.5:c.311A>C

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PP3_StrongPP5_Very_Strong

The NM_031885.5(BBS2):c.311A>C(p.Asp104Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,614,032 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. D104D) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

BBS2
NM_031885.5 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:14

Conservation

PhyloP100: 7.86

Publications

10 publications found

Variant links:

Genes affected

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]

BBS2 Gene-Disease associations (from GenCC):

Bardet-Biedl syndrome 2
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Myriad Women’s Health
ciliopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
retinitis pigmentosa 74
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
retinitis pigmentosa
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Bardet-Biedl syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

BBS2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 12 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.958

PP5

Variant 16-56514487-T-G is Pathogenic according to our data. Variant chr16-56514487-T-G is described in ClinVar as Pathogenic. ClinVar VariationId is 4577.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_031885.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
BBS2	NM_031885.5	MANE Select	c.311A>C	p.Asp104Ala	missense	Exon 2 of 17	NP_114091.4
BBS2	NM_001377456.1		c.311A>C	p.Asp104Ala	missense	Exon 2 of 18	NP_001364385.1
BBS2	NR_165293.1		n.473A>C		non_coding_transcript_exon	Exon 2 of 17

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
BBS2	ENST00000245157.11	TSL:1 MANE Select	c.311A>C	p.Asp104Ala	missense	Exon 2 of 17	ENSP00000245157.5
BBS2	ENST00000565781.6	TSL:1	n.325A>C		non_coding_transcript_exon	Exon 2 of 12
BBS2	ENST00000682360.1		c.-287A>C		5_prime_UTR_premature_start_codon_gain	Exon 2 of 18	ENSP00000508007.1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152178

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000865

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:

0.0000437

AC:

AN:

251464

AF XY:

0.0000589

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000992

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000287

AC:

AN:

1461854

Hom.:

Cov.:

AF XY:

0.0000371

AC XY:

AN XY:

727230

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00115

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111978

Other (OTH)

AF:

0.0000993

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000263

AC:

AN:

152178

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74338

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41442

American (AMR)

AF:

0.00

AC:

AN:

15274

Ashkenazi Jewish (ASJ)

AF:

0.000865

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.538

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.0000567

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:14

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bardet-Biedl syndrome

Pathogenic:3

Dec 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with alanine, which is neutral and non-polar, at codon 104 of the BBS2 protein (p.Asp104Ala). This variant is present in population databases (rs121908179, gnomAD 0.1%). This missense change has been observed in individuals with Bardet-Biedl syndrome (PMID: 11567139, 21344540, 21642631, 23829372). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 4577). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt BBS2 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects BBS2 function (PMID: 20498079). For these reasons, this variant has been classified as Pathogenic.

Jun 30, 2016

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: The c.311A>C (p.D104A) in BBS2 gene is a missense change that alters a conserved nucleotide and 5/5 in silico tools predict deleterious outcome. The variant was observed in the large and broad cohorts of the ExAC project at an allele frequency of 0.00005 exclusively in individuals of European descent (0.000075). This frequency does not exceed the maximal expected allele frequency for a pathogenic variant in BBS2 gene (0.0008). Fedick (2014) reports the carrier frequency of 0.473% (0.0071%) for Jewish population. The variant of interest has been reported in multiple BBS pts in compound heterozygous state and in 2 homozygous individuals presented with nonsyndromic autosomal recessive RP (Shevach, 2014). Taking together, the variant was classified as Pathogenic.

Apr 26, 2023

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

Retinitis pigmentosa 74

Pathogenic:2

May 04, 2022

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:curation

The heterozygous p.Asp104Ala variant in BBS2 was identified by our study, along with another pathogenic variant, in 1 individual with retinitis pigmentosa 74. The variant has been reported in at least 4 Ashkenazi Jewish individuals with retinitis pigmentosa 74 (PMID: 23829372), and has been identified in 0.1% (10/10080) of Ashkenazi Jewish and 0.0009% (1/113746) of European non-Finnish chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs121908179). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (Variation ID: 4577) as pathogenic by Integrated Genetics/Laboratory Corporation of America, Invitae, OMIM, and Sharon lab, Hadassah-Hebrew University Medical Center, and as likely pathogenic by Counsyl and Fulgent Genetics. Animal models in zebrafish have shown that this variant causes retinitis pigmentosa 74 (PMID: 20498079). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. The presence of this variant in 2 affected homozygotes, in combination with a reported pathogenic variant, and in 4 individuals with retinitis pigmentosa 74 increases the likelihood that the p.Asp104Ala variant is pathogenic (VariationID: 4578; PMID: 23829372). In summary, this variant meets criteria to be classified as pathogenic for retinitis pigmentosa 74 in an autosomal recessive manner based on its disease-causing effect in an animal model, and its homozygous occurrence and occurrence with other pathogenic variants in trans in affected individuals. ACMG/AMP Criteria applied: PS3, PM3_strong, PP3 (Richards 2015).

Mar 01, 2015

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

Bardet-Biedl syndrome 2

Pathogenic:2

Jan 30, 2017

Counsyl

Significance:Likely pathogenic

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.

Mar 26, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Bardet-Biedl syndrome 2;C4225281:Retinitis pigmentosa 74

Pathogenic:2

Feb 23, 2022

New York Genome Center

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jan 31, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Retinitis pigmentosa

Pathogenic:2

Apr 01, 2021

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:curation

The p.Asp104Ala variant in BBS2 was identified in an individual with Retinitis pigmentosa, via a collaborative study between the Broad Institute's Center for Mendelian Genomics and the Pierce lab (https://oculargenomics.meei.harvard.edu/labs/pierce-lab/lab-members/). Through a review of available evidence we were able to apply the following criteria: PS3, PM2, PM3, PP1, PP3. Based on this evidence we have classified this variant as Pathogenic. If you have any questions about the classification please reach out to the Pierce Lab.

Jun 23, 2019

Sharon lab, Hadassah-Hebrew University Medical Center

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:research

Bardet-biedl syndrome 1/2, digenic

Pathogenic:1

Mar 01, 2015

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

not provided

Pathogenic:1

Dec 18, 2024

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Published functional studies demonstrate a damaging effect suggestive of a dominant negative mechanism (PMID: 20498079); This variant is associated with the following publications: (PMID: 25541840, 19402160, 31964843, 35112343, 11567139, 23829372, 31456290, 32037395, 20498079)

BBS2-related disorder

Pathogenic:1

Aug 20, 2024

PreventionGenetics, part of Exact Sciences

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

The BBS2 c.311A>C variant is predicted to result in the amino acid substitution p.Asp104Ala. This sequence variant has been reported in multiple individuals with Bardet-Biedl syndrome 2, retinitis pigmentosa 74, and cone-rod dystrophy (Katsanis et al. 2001. PubMed ID: 11567139; Consugar et al 2015. PubMed ID: 25412400; Shevach et al 2015. PubMed ID: 25541840). This variant is reported in 0.099% of alleles in individuals of Ashkenazi Jewish descent in gnomAD (http://gnomad.broadinstitute.org/variant/16-56548399-T-G). This variant is interpreted as pathogenic.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.78

BayesDel_addAF

Pathogenic

0.39

BayesDel_noAF

Pathogenic

0.33

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.82

Eigen

Pathogenic

0.86

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Uncertain

0.97

LIST_S2

Uncertain

0.95

M_CAP

Benign

0.040

MetaRNN

Pathogenic

0.96

MetaSVM

Uncertain

0.47

PhyloP100

7.9

PrimateAI

Uncertain

0.70

PROVEAN

Pathogenic

-5.7

REVEL

Pathogenic

0.86

Sift

Uncertain

0.0040

Sift4G

Uncertain

0.027

Vest4

0.93

MutPred

0.94

Loss of sheet (P = 0.0181)

MVP

0.89

MPC

1.0

ClinPred

0.95

GERP RS

5.4

gMVP

0.90

Mutation Taster

=2/98

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over