1-55008524-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_057176.3(BSND):c.859G>T(p.Glu287Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000178 in 1,461,872 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 Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. E287E) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: BSND NM_057176.3 stop_gained
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 1.50

Genes affected

BSND (HGNC:16512): (barttin CLCNK type accessory subunit beta) This gene encodes an essential beta subunit for CLC chloride channels. These heteromeric channels localize to basolateral membranes of renal tubules and of potassium-secreting epithelia of the inner ear. Mutations in this gene have been associated with Bartter syndrome with sensorineural deafness. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.108 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BSND	NM_057176.3	c.859G>T	p.Glu287Ter	stop_gained	4/4	ENST00000651561.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BSND	ENST00000651561.1	c.859G>T	p.Glu287Ter	stop_gained	4/4		NM_057176.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251428 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135892

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000178 AC: 26 AN: 1461872 Hom.: 0 Cov.: 31 AF XY: 0.0000151 AC XY: 11 AN XY: 727228

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: 0.0000234

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000478 Hom.: 0

Bravo AF: 0.0000302

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jun 28, 2016

The p.Glu287X variant in BSND has not been previously reported in individuals wi th hearing loss or Bartter syndrome, but has been identified in 1/66718 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitu te.org; dbSNP rs376784896). Although this variant has been seen in the general p opulation, its frequency is not high enough to rule out a pathogenic role. This nonsense variant leads to a premature termination codon at position 287. This al teration occurs within the last exon and is likely to escape nonsense mediated d ecay (NMD) and to result in a truncated product 10% shorter than the normal prot ein. It is unclear whether the truncation impacts the protein function. In summa ry, the clinical significance of the p.Glu287X variant is uncertain. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 27, 2021

The c.859G>T (p.E287*) alteration, located in exon 4 (coding exon 4) of the BSND gene, consists of a G to T substitution at nucleotide position 859. This changes the amino acid from a glutamic acid (E) to a stop codon at amino acid position 287. Premature stop codons are typically deleterious in nature (Richards, 2015). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Bartter disease type 4A Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Dec 15, 2018

This variant is a stop-gained variant, which was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018) and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score for this variant, it could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change. No publications were found based on this search. This variant is located in the last exon or in the last 50 bp of the penultimate exon and may escape nonsense-mediated decay. Due to the potential impact of stop-gained variants and the lack of clarifying evidence, this variant is classified as a variant of unknown significance but suspicious for pathogenicity for this disease. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 19, 2022

This sequence change creates a premature translational stop signal (p.Glu287*) in the BSND gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 34 amino acid(s) of the BSND protein. This variant is present in population databases (rs376784896, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with BSND-related conditions. ClinVar contains an entry for this variant (Variation ID: 505171). 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. -

Bartter syndrome Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Dec 15, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.29
Cadd	Pathogenic	35
Dann	Uncertain	0.99
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.28
FATHMM_MKL	Benign	0.66	D
MutationTaster	Benign	1.0	D
Vest4		0.47
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs376784896; hg19: chr1-55474197;