rs148808295

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_031885.5(BBS2):c.358G>A(p.Ala120Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000601 in 1,613,830 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00028 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

BBS2
NM_031885.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 7.79

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 Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BBS2	NM_031885.5 linkuse as main transcript	c.358G>A	p.Ala120Thr	missense_variant	3/17	ENST00000245157.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BBS2	ENST00000245157.11 linkuse as main transcript	c.358G>A	p.Ala120Thr	missense_variant	3/17	1	NM_031885.5	P1

Frequencies

GnomAD3 genomes

AF:

0.000276

AC:

AN:

152110

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000845

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000735

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000796

AC:

AN:

251246

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135798

show subpopulations

Gnomad AFR exome

AF:

0.00105

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000376

AC:

AN:

1461720

Hom.:

Cov.:

AF XY:

0.0000344

AC XY:

AN XY:

727158

show subpopulations

Gnomad4 AFR exome

AF:

0.00119

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000719

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.000276

AC:

AN:

152110

Hom.:

Cov.:

AF XY:

0.000337

AC XY:

AN XY:

74292

show subpopulations

Gnomad4 AFR

AF:

0.000845

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.000478

Alfa

AF:

0.000137

Hom.:

Bravo

AF:

0.000370

ESP6500AA

AF:

0.00114

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000107

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 16, 2022

The c.358G>A (p.A120T) alteration is located in exon 3 (coding exon 3) of the BBS2 gene. This alteration results from a G to A substitution at nucleotide position 358, causing the alanine (A) at amino acid position 120 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Bardet-Biedl syndrome 2

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Oct 28, 2019

- -

BBS2-related disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Feb 15, 2024

The BBS2 c.358G>A variant is predicted to result in the amino acid substitution p.Ala120Thr. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.092% of alleles in individuals of African descent in gnomAD, which may be too common to be an undocumented primary cause of disease. Although we suspect that this variant may be benign, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Bardet-Biedl syndrome 2;C4225281:Retinitis pigmentosa 74

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

May 04, 2022

- -

Bardet-Biedl syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 17, 2022

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 120 of the BBS2 protein (p.Ala120Thr). This variant is present in population databases (rs148808295, gnomAD 0.1%). This variant has not been reported in the literature in individuals affected with BBS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 410986). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt BBS2 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.014

BayesDel_noAF

Pathogenic

0.16

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Uncertain

0.51

D;.

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.78

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.86

D;.

M_CAP

Uncertain

0.18

MetaRNN

Uncertain

0.54

D;D

MetaSVM

Uncertain

0.27

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.64

PROVEAN

Benign

-1.6

N;N

Sift

Benign

0.034

D;D

Sift4G

Benign

0.063

T;T

Vest4

0.83

MVP

0.84

MPC

0.69

ClinPred

0.13

GERP RS

5.9

gMVP

0.64

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

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