rs779690256

Positions:

chr16-56506137-G-A

Variant summary

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

The NM_031885.5(BBS2):c.700C>T(p.Arg234Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,613,498 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: 0.000015 ( 0 hom. )

Consequence

BBS2
NM_031885.5 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9U:1

Conservation

PhyloP100: 7.93

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 16-56506137-G-A is Pathogenic according to our data. Variant chr16-56506137-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 554001.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-56506137-G-A is described in Lovd as [Pathogenic]. Variant chr16-56506137-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BBS2	NM_031885.5 linkuse as main transcript	c.700C>T	p.Arg234Ter	stop_gained	6/17	ENST00000245157.11	NP_114091.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BBS2	ENST00000245157.11 linkuse as main transcript	c.700C>T	p.Arg234Ter	stop_gained	6/17	1	NM_031885.5	ENSP00000245157	P1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152050

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:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000279

AC:

AN:

251228

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135792

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

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:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1461448

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727030

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000144

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152050

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74262

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:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bardet-Biedl syndrome 2

Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Medical Genetics Center, Maternal and Child Health Hospital of Hubei Province	Jul 03, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Sep 21, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 22, 2024	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Jul 23, 2020	- -

Bardet-Biedl syndrome

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 13, 2023	This sequence change creates a premature translational stop signal (p.Arg234*) 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 (rs779690256, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with clinical features of a ciliopathy disorder (PMID: 15666242, 27894351). ClinVar contains an entry for this variant (Variation ID: 554001). 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	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 05, 2019	Variant summary: BBS2 c.700C>T (p.Arg234X) 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. The variant allele was found at a frequency of 2.8e-05 in 251228 control chromosomes (gnomAD). c.700C>T has been reported in the literature in compound heterozygous and homozygous states in individuals affected with Bardet-Biedl Syndrome (Deveault_2011, Karmous-Benailly_2005, Patel_2016, Shaheen_2016). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. A ClinVar submitter (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

May 12, 2020

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 31054281, 15666242, 25525159) -

BBS2-related disorder

Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 01, 2024

The BBS2 c.700C>T variant is predicted to result in premature protein termination (p.Arg234*). This variant has been reported in individuals with Bardet-Biedl syndrome (Karmous-Benailly et al 2005. PubMed ID: 15666242; Shaheen et al 2016. PubMed ID: 27894351; Gao et al 2019. PubMed ID: 31054281). This variant is reported in 0.0056% of alleles in individuals of Latino descent in gnomAD. Nonsense variants in BBS2 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Bardet-Biedl syndrome 2;C4225281:Retinitis pigmentosa 74

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Feb 02, 2022

- -

Retinal dystrophy

Uncertain:1

Uncertain significance, flagged submission

research

Dept Of Ophthalmology, Nagoya University

Oct 01, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.66

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.96

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Pathogenic

0.99

MutationTaster

Benign

1.0

A;A

Vest4

0.85

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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