11-66510666-G-T

Position:

• chr11-66510666-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_024649.5(BBS1):​c.7G>T​(p.Ala3Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,796 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BBS1 NM_024649.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 2.05

Genes affected

BBS1 (HGNC:966): (Bardet-Biedl syndrome 1) Mutations in this gene have been observed in patients with the major form (type 1) of Bardet-Biedl syndrome. The encoded protein may play a role in eye, limb, cardiac and reproductive system development. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.116856486).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BBS1	NM_024649.5	c.7G>T	p.Ala3Ser	missense_variant	1/17	ENST00000318312.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BBS1	ENST00000318312.12	c.7G>T	p.Ala3Ser	missense_variant	1/17	1	NM_024649.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461796 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727184

Gnomad4 AFR exome AF: 0.00

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

BBS1-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 04, 2023

The BBS1 c.7G>T variant is predicted to result in the amino acid substitution p.Ala3Ser. To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Bardet-Biedl syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 23, 2022

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 3 of the BBS1 protein (p.Ala3Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BBS1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0"). 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	0.11
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Benign	17
DANN	Benign	0.96
DEOGEN2	Benign	0.16	T;.;T;.;.
Eigen	Benign	-0.60
Eigen_PC	Benign	-0.58
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.76	T;T;T;T;T
M_CAP	Benign	0.081	D
MetaRNN	Benign	0.12	T;T;T;T;T
MetaSVM	Uncertain	0.30	D
MutationAssessor	Benign	1.6	L;.;.;L;.
MutationTaster	Benign	0.99	D;N;N;N
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.39	N;N;N;N;.
REVEL	Uncertain	0.30
Sift	Pathogenic	0.0	D;D;D;T;.
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		0.044	B;.;B;.;.
Vest4		0.41
MutPred		0.20		Gain of phosphorylation at A3 (P = 0.0033);Gain of phosphorylation at A3 (P = 0.0033);Gain of phosphorylation at A3 (P = 0.0033);Gain of phosphorylation at A3 (P = 0.0033);Gain of phosphorylation at A3 (P = 0.0033);
MVP		0.80
MPC		0.14
ClinPred		0.42	T
GERP RS		4.0
Varity_R		0.10
gMVP		0.41

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

Other links and lift over

dbSNP: rs562874449; hg19: chr11-66278137;