rs28940274

Positions:

• chr11-61955723-T-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_004183.4(BEST1):​c.253T>C​(p.Tyr85His) variant causes a missense 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 Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: BEST1 NM_004183.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5 O:1
• Conservation: PhyloP100: 7.88

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 16 ACMG points.

• PM1: In a helix (size 22) in uniprot entity BEST1_HUMAN there are 50 pathogenic changes around while only 0 benign (100%) in NM_004183.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 11-61955723-T-C is Pathogenic according to our data. Variant chr11-61955723-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 2728.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-61955723-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BEST1	NM_004183.4	c.253T>C	p.Tyr85His	missense_variant	4/11	ENST00000378043.9	NP_004174.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BEST1	ENST00000378043.9	c.253T>C	p.Tyr85His	missense_variant	4/11	1	NM_004183.4	ENSP00000367282.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1384742 Hom.: 0 Cov.: 38 AF XY: 0.00 AC XY: 0 AN XY: 683312

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Vitelliform macular dystrophy 2 Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Jul 01, 1998	- -
Likely pathogenic, no assertion criteria provided	research	Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet	Apr 01, 2018	- -

Retinal dystrophy Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg	Jan 01, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Blueprint Genetics	Feb 27, 2019	- -

not provided Pathogenic:1 Other:1

not provided, no classification provided	literature only	Retina International	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 03, 2024	This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 85 of the BEST1 protein (p.Tyr85His). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal dominant Best vitelliform macular dystrophy (PMID: 20375334, 21473666). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 2728). 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%. Experimental studies have shown that this missense change affects BEST1 function (PMID: 11904445, 17110374, 21330666, 23880862). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	H;.
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-4.8	D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.96
MutPred		0.94		Loss of helix (P = 0.2022);.;
MVP		0.99
MPC		1.1
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.97
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs28940274; hg19: chr11-61723195;