rs121908180

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_031885.5(BBS2):c.646C>T(p.Arg216Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000217 in 1,613,762 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 (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

BBS2
NM_031885.5 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 5.23

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 16-56506191-G-A is Pathogenic according to our data. Variant chr16-56506191-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 4583.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-56506191-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BBS2	NM_031885.5 linkuse as main transcript	c.646C>T	p.Arg216Ter	stop_gained	6/17	ENST00000245157.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BBS2	ENST00000245157.11 linkuse as main transcript	c.646C>T	p.Arg216Ter	stop_gained	6/17	1	NM_031885.5	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152102

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251182

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135762

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000233

AC:

AN:

1461660

Hom.:

Cov.:

AF XY:

0.0000206

AC XY:

AN XY:

727130

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000270

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152102

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74306

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000351

Hom.:

Bravo

AF:

0.00000378

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bardet-Biedl syndrome 2

Pathogenic:4

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 11, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 01, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The stop gained c.646C>T p.Arg216Ter variant in BBS2 gene has been reported in compound heterozygous state in individuals affected with Bardet-Biedl syndrome 2 Hjortshøj TD et al. 2010; Karmous-Benailly H et al. 2005. The p.Arg216Ter variant has allele frequency 0.001% in gnomAD Exomes and is novel not in any individuals in 1000 Genomes. This variant has been reported to the ClinVar database as Likely Pathogenic / Pathogenic multiple submitters. The nucleotide change c.646C>T in BBS2 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. This variant is predicted to cause loss of normal protein function through protein truncation. Loss-of-function variants in BBS2 are known to be pathogenic Ece Solmaz A et al. 2015. For these reasons, this variant has been classified as Pathogenic. -

Bardet-Biedl syndrome

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 18, 2021	Variant summary: BBS2 c.646C>T (p.Arg216X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 1.2e-05 in 251182 control chromosomes. c.646C>T has been reported in the literature in multiple individuals affected with Bardet-Biedl Syndrome. These data indicate that the variant is very likely to be associated with disease. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Dec 26, 2023	This sequence change creates a premature translational stop signal (p.Arg216*) in the BBS2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BBS2 are known to be pathogenic (PMID: 11285252, 20177705, 24608809, 26518167). This variant is present in population databases (rs121908180, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with Bardet-Biedl syndrome (PMID: 11567139, 20120035). ClinVar contains an entry for this variant (Variation ID: 4583). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	research	SN ONGC Dept of Genetics and Molecular biology Vision Research Foundation	-	- -

Bardet-biedl syndrome 2/6, digenic

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Sep 21, 2001

- -

Retinal dystrophy

Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet

Apr 01, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.51

BayesDel_noAF

Pathogenic

0.63

Cadd

Pathogenic

Dann

Uncertain

1.0

Eigen

Pathogenic

0.80

Eigen_PC

Pathogenic

0.68

FATHMM_MKL

Uncertain

0.97

MutationTaster

Benign

1.0

A;A

Vest4

0.87

GERP RS

4.8

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.23

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.23

Position offset: 33

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