chr16-56484820-G-A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong

The NM_031885.5(BBS2):c.2107C>T(p.Arg703*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000929 in 1,613,992 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

BBS2
NM_031885.5 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11

Conservation

PhyloP100: 5.16

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 links:

ENSG00000288725 (HGNC:):

ENSG00000288725 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0272 CDS is truncated, and there are 0 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 16-56484820-G-A is Pathogenic according to our data. Variant chr16-56484820-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 496478.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BBS2	NM_031885.5 link	c.2107C>T	p.Arg703*	stop_gained	Exon 17 of 17	ENST00000245157.11	NP_114091.4	Q9BXC9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BBS2	ENST00000245157.11 link	c.2107C>T	p.Arg703*	stop_gained	Exon 17 of 17	1	NM_031885.5	ENSP00000245157.5		Q9BXC9
ENSG00000288725	ENST00000684388.1 link	n.1027C>T		non_coding_transcript_exon_variant	Exon 8 of 14			ENSP00000507647.1		A0A804HJU2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152134

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000318

AC:

AN:

251378

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135858

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000272

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000889

AC:

AN:

1461740

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727186

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000126

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152252

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74436

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.00000993

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bardet-Biedl syndrome 2

Pathogenic:3

May 15, 2017

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Sep 16, 2020

Natera, Inc.

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Mar 20, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Retinitis pigmentosa 74

Pathogenic:2

Apr 08, 2021

Ocular Genomics Institute, Massachusetts Eye and Ear

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

The BBS2 c.2107C>T variant was identified in an individual with retinitis pigmentosa with a presumed recessive inheritance pattern. Through a review of available evidence we were able to apply the following criteria: PVS1, PM2. Based on this evidence we have classified this variant as Likely Pathogenic. -

May 22, 2022

3billion, Medical Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.003%). Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through protein truncation. The predicted truncated protein may be shortened by less than 10%. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000496478 / PMID: 21344540). Therefore, this variant is classified as likely pathogenic according to the recommendation of ACMG/AMP guideline. -

Bardet-Biedl syndrome

Pathogenic:2

Nov 27, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg703*) in the BBS2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 19 amino acid(s) of the BBS2 protein. This variant is present in population databases (rs567573386, gnomAD 0.03%). This premature translational stop signal has been observed in individual(s) with BBS2-related disease (PMID: 21344540, 25999675; internal data). ClinVar contains an entry for this variant (Variation ID: 496478). For these reasons, this variant has been classified as Pathogenic. -

Jun 22, 2017

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Pathogenic:1

Jan 24, 2017

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

BBS2-related disorder

Pathogenic:1

Jan 08, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The BBS2 c.2107C>T variant is predicted to result in premature protein termination (p.Arg703*). This variant has been reported in the homozygous state or with a second BBS2 variant in individuals with Bardet-Biedl syndrome (Deveault et al. 2011. PubMed ID: 21344540; Supplemental Table 1, Forsythe et al. 2016. PubMed ID: 27659767; Table S3, Fu et al. 2022. PubMed ID: 36307859) and reported in the homozygous state in an individual with retinitis pigmentosa (Xu et al. 2015. PubMed ID: 25999675). In addition, at PreventionGenetics, this variant has been seen in the homozygous or compound heterozygous states in individuals with features of Bardet-Biedl syndrome (Internal Data). This variant is reported in 0.027% of alleles in individuals of East Asian descent in a large population database. Nonsense variants in BBS2 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -

Retinal dystrophy

Pathogenic:1

Jan 01, 2018

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Bardet-Biedl syndrome 2;C4225281:Retinitis pigmentosa 74

Pathogenic:1

Feb 29, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.38

BayesDel_noAF

Pathogenic

0.62

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Uncertain

0.92

Vest4

0.48, 0.73

GERP RS

5.3

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over