rs779690256

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_031885.5(BBS2):c.700C>T(p.Arg234*) 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

Publications

4 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 16 ACMG points.

PVS1

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

PP5

Variant 16-56506137-G-A is Pathogenic according to our data. Variant chr16-56506137-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 554001.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.700C>T	p.Arg234*	stop_gained	Exon 6 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.700C>T	p.Arg234*	stop_gained	Exon 6 of 17	1	NM_031885.5	ENSP00000245157.5		Q9BXC9

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

GnomAD2 exomes

AF:

0.0000279

AC:

AN:

251228

AF XY:

0.0000368

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 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

African (AFR)

AF:

0.00

AC:

AN:

33472

American (AMR)

AF:

0.0000447

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.0000756

AC:

AN:

39676

South Asian (SAS)

AF:

0.00

AC:

AN:

86244

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53386

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.0000144

AC:

AN:

1111676

Other (OTH)

AF:

0.0000166

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.452

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:

0.00000658

AC:

AN:

152050

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74262

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41414

American (AMR)

AF:

0.00

AC:

AN:

15256

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10574

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68018

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000359

Hom.:

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

Feb 22, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 21, 2017

Counsyl

Significance: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. -

Jul 03, 2022

Medical Genetics Center, Maternal and Child Health Hospital of Hubei Province

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 23, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Bardet-Biedl syndrome

Pathogenic:2

Feb 09, 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.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. -

Aug 05, 2019

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

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

May 12, 2020

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Mar 01, 2024

PreventionGenetics, part of Exact Sciences

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

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

May 31, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Retinal dystrophy

Uncertain:1

Oct 01, 2023

Dept Of Ophthalmology, Nagoya University

Significance:Uncertain significance

Review Status:flagged submission

Collection Method:research

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.66

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

0.96

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Pathogenic

0.99

PhyloP100

7.9

Vest4

0.85

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=2/198

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over