rs267606677

Positions:

• chr11-61957430-A-G

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_001363593.2(BEST1):​c.-496A>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BEST1 NM_001363593.2 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4 O:1
• Conservation: PhyloP100: 7.26

Genes affected

BEST1 (HGNC:12703): (bestrophin 1) This gene encodes a member of the bestrophin gene family. This small gene family is characterized by proteins with a highly conserved N-terminus with four to six transmembrane domains. Bestrophins may form chloride ion channels or may regulate voltage-gated L-type calcium-ion channels. Bestrophins are generally believed to form calcium-activated chloride-ion channels in epithelial cells but they have also been shown to be highly permeable to bicarbonate ion transport in retinal tissue. Mutations in this gene are responsible for juvenile-onset vitelliform macular dystrophy (VMD2), also known as Best macular dystrophy, in addition to adult-onset vitelliform macular dystrophy (AVMD) and other retinopathies. Alternative splicing results in multiple variants encoding distinct isoforms.[provided by RefSeq, Nov 2008]

BEST1 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 11-61957430-A-G is Pathogenic according to our data. Variant chr11-61957430-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2749.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-61957430-A-G is described in Lovd as [Likely_pathogenic]. Variant chr11-61957430-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BEST1	NM_004183.4	c.680A>G	p.Tyr227Cys	missense_variant	6/11	ENST00000378043.9	NP_004174.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BEST1	ENST00000378043.9	c.680A>G	p.Tyr227Cys	missense_variant	6/11	1	NM_004183.4	ENSP00000367282.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

Alfa AF: 0.00152 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2 Other:1

not provided, no classification provided	literature only	Retina International	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 29, 2022	For these reasons, this variant has been classified as Pathogenic. 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 BEST1 protein function. ClinVar contains an entry for this variant (Variation ID: 2749). This variant is also known as p.Tyr167Cys. This missense change has been observed in individuals with autosomal dominant Best disease (PMID: 9700209, 26418331, 28559085, 30582078). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 227 of the BEST1 protein (p.Tyr227Cys). -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 14, 2022	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 24560797, 19853238, 26418331, 9700209, 10798642, 30582078, 27548040, 28559085) -

Vitelliform macular dystrophy 2 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 2009

- -

Retinitis pigmentosa 50 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 2009

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.;D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Pathogenic	0.78	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-8.4	D;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	D;D;D
Vest4		0.95
MutPred		0.94		Loss of stability (P = 0.0484);.;.;
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.92
gMVP		0.95

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs267606677; hg19: chr11-61724902;