rs765333778

Positions:

• chr11-61951945-C-T

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 16P and 1B. PM1 PM5 PP3_Strong PP5_Very_Strong BS2_Supporting

The NM_004183.4(BEST1):​c.139C>T​(p.Arg47Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000089 in 1,461,468 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R47H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: BEST1 NM_004183.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.81

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]

ACMG classification

Verdict is Pathogenic. Variant got 15 ACMG points.

• PM1: In a helix (size 24) in uniprot entity BEST1_HUMAN there are 21 pathogenic changes around while only 0 benign (100%) in NM_004183.4
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-61951946-G-A is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.976
• PP5: Variant 11-61951945-C-T is Pathogenic according to our data. Variant chr11-61951945-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 305117.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-61951945-C-T is described in Lovd as [Likely_pathogenic]. Variant chr11-61951945-C-T is described in Lovd as [Likely_pathogenic].
• BS2: High AC in GnomAdExome4 at 13 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BEST1	NM_004183.4	c.139C>T	p.Arg47Cys	missense_variant	2/11	ENST00000378043.9	NP_004174.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BEST1	ENST00000378043.9	c.139C>T	p.Arg47Cys	missense_variant	2/11	1	NM_004183.4	ENSP00000367282	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251230 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135802

Gnomad AFR exome AF: 0.00

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: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000890 AC: 13 AN: 1461468 Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3 AN XY: 727034

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000899

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000621 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Mar 09, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 29, 2024	This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 47 of the BEST1 protein (p.Arg47Cys). This variant is present in population databases (rs765333778, gnomAD 0.003%). This missense change has been observed in individuals with clinical features of autosomal recessive bestrophinopathy (PMID: 21273940, 22162627, 28590961). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 305117). 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 with a positive predictive value of 95%. This variant disrupts the p.Arg47 amino acid residue in BEST1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 29976937, 30498755). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.60	D
Eigen	Benign	0.19
Eigen_PC	Benign	0.062
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.49	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.2	M
MutationTaster	Benign	1.0	D;D;D;D;D;D
PROVEAN	Benign	-1.9	N
REVEL	Pathogenic	0.67
Sift	Uncertain	0.0070	D
Sift4G	Uncertain	0.0050	D
Polyphen		1.0	D
Vest4		0.81
MutPred		0.80		Gain of catalytic residue at I45 (P = 0.1438);
MVP		0.98
ClinPred		0.34	T
GERP RS		2.1
Varity_R		0.37

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: rs765333778; hg19: chr11-61719417;