11-61950428-G-T

Position:

• chr11-61950428-G-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1 PM2 PP3_Strong PP5_Moderate

The NM_004183.4(BEST1):​c.-37+1G>T variant causes a splice donor change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: BEST1 NM_004183.4 splice_donor
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 2.46

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 16 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 6, offset of 11, new splice context is: aagGTgccc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 11-61950428-G-T is Pathogenic according to our data. Variant chr11-61950428-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 438184.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr11-61950428-G-T is described in Lovd as [Pathogenic]. Variant chr11-61950428-G-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BEST1	NM_004183.4	c.-37+1G>T		splice_donor_variant		ENST00000378043.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BEST1	ENST00000378043.9	c.-37+1G>T		splice_donor_variant		1	NM_004183.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 586 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 346

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR 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: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal recessive bestrophinopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Institute of Medical Molecular Genetics, University of Zurich

Jan 30, 2021

- -

Retinal dystrophy Pathogenic:1

Pathogenic, no assertion criteria provided

research

NIHR Bioresource Rare Diseases, University of Cambridge

Jan 01, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.12
CADD	Pathogenic	27
DANN	Uncertain	0.99

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.89		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.23		Position offset: 10
DS_DL_spliceai		0.89		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555096248; hg19: chr11-61717900;