chr10-119672353-G-GC

Position:

• chr10-119672353-G-GC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004281.4(BAG3):​c.607dup​(p.Arg203ProfsTer52) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. P202P) has been classified as Benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BAG3 NM_004281.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 3.13

Genes affected

BAG3 (HGNC:939): (BAG cochaperone 3) BAG proteins compete with Hip for binding to the Hsc70/Hsp70 ATPase domain and promote substrate release. All the BAG proteins have an approximately 45-amino acid BAG domain near the C terminus but differ markedly in their N-terminal regions. The protein encoded by this gene contains a WW domain in the N-terminal region and a BAG domain in the C-terminal region. The BAG domains of BAG1, BAG2, and BAG3 interact specifically with the Hsc70 ATPase domain in vitro and in mammalian cells. All 3 proteins bind with high affinity to the ATPase domain of Hsc70 and inhibit its chaperone activity in a Hip-repressible manner. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 10-119672353-G-GC is Pathogenic according to our data. Variant chr10-119672353-G-GC is described in ClinVar as [Pathogenic]. Clinvar id is 410229.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BAG3	NM_004281.4	c.607dup	p.Arg203ProfsTer52	frameshift_variant	3/4	ENST00000369085.8	NP_004272.2
BAG3	XM_005270287.2	c.607dup	p.Arg203ProfsTer52	frameshift_variant	3/4		XP_005270344.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BAG3	ENST00000369085.8	c.607dup	p.Arg203ProfsTer52	frameshift_variant	3/4	1	NM_004281.4	ENSP00000358081	P1
BAG3	ENST00000450186.1	c.433dup	p.Arg145ProfsTer52	frameshift_variant	4/5	5		ENSP00000410036

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Myofibrillar myopathy 6;C3151293:Dilated cardiomyopathy 1HH Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 29, 2023

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 410229). This variant has not been reported in the literature in individuals affected with BAG3-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Arg203Profs*52) in the BAG3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BAG3 are known to be pathogenic (PMID: 21353195, 25008357). -

Dilated cardiomyopathy 1HH Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 25, 2016

This sequence change inserts 1 nucleotide in exon 3 of the BAG3 mRNA (c.607dupC), causing a frameshift at codon 203. This creates a premature translational stop signal (p.Arg203Profs*52) and is expected to result in an absent or disrupted protein product. While this particular variant has not been reported in the literature, loss-of-function variants in BAG3 are known to be pathogenic (PMID: 21353195, 25008357). For these reasons, this variant has been classified as Pathogenic. -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 23, 2021

The c.607dupC variant, located in coding exon 3 of the BAG3 gene, results from a duplication of C at nucleotide position 607, causing a translational frameshift with a predicted alternate stop codon (p.R203Pfs*52). This alteration has not been previously reported; however, loss of function alterations have been reported in numerous cases of familial dilated cardiomyopathy, including many families with strong segregation with disease (Norton N et al. Am J Hum Genet. 2011;88(3):273-82; Villard E et al. Eur Heart J. 2011;32(9):1065-76; Chami N et al. Can J Cardiol. 2014;30(12):1655-61; Feldman AM et al. J Cell Physiol. 2014;229(11):1697-702; Franaszczyk M et al. J Transl Med. 2014;12:192; van Spaendonck-Zwarts KY et al. Eur Heart J. 2014;35(32):2165-73). In addition, in Norton et al. 2011, BAG3 knockdown in a zebrafish model showed heart failure with decreased fractional shortening and pericardial effusion. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

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: rs1554877224; hg19: chr10-121431865;