rs397515934

Variant names:

• chr11-47341139-CA-C
• rs397515934
• NM_000256.3:c.1895delT

Variant summary

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

The NM_000256.3(MYBPC3):​c.1895delT​(p.Met632ArgfsTer31) variant causes a frameshift, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000694 in 1,439,988 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MYBPC3 NM_000256.3 frameshift, splice_region
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 8.89

Genes affected

MYBPC3 (HGNC:7551): (myosin binding protein C3) MYBPC3 encodes the cardiac isoform of myosin-binding protein C. Myosin-binding protein C is a myosin-associated protein found in the cross-bridge-bearing zone (C region) of A bands in striated muscle. MYBPC3 is expressed exclusively in heart muscle and is a key regulator of cardiac contraction. Mutations in this gene are a frequent cause of familial hypertrophic cardiomyopathy. [provided by RefSeq, May 2022]

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 11-47341139-CA-C is Pathogenic according to our data. Variant chr11-47341139-CA-C is described in ClinVar as [Pathogenic]. Clinvar id is 42581.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-47341139-CA-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYBPC3	NM_000256.3	c.1895delT	p.Met632ArgfsTer31	frameshift_variant, splice_region_variant	Exon 19 of 35	ENST00000545968.6	NP_000247.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYBPC3	ENST00000545968.6	c.1895delT	p.Met632ArgfsTer31	frameshift_variant, splice_region_variant	Exon 19 of 35	5	NM_000256.3	ENSP00000442795.1
MYBPC3	ENST00000399249.6	c.1895delT	p.Met632ArgfsTer31	frameshift_variant, splice_region_variant	Exon 18 of 34	5		ENSP00000382193.2
MYBPC3	ENST00000544791.1	n.1895delT		splice_region_variant, non_coding_transcript_exon_variant	Exon 19 of 27	5		ENSP00000444259.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.94e-7 AC: 1 AN: 1439988 Hom.: 0 Cov.: 36 AF XY: 0.00000140 AC XY: 1 AN XY: 713772

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: 0.0000121

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:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:2

Nov 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Met632Argfs*31) in the MYBPC3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MYBPC3 are known to be pathogenic (PMID: 19574547). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 25611685). ClinVar contains an entry for this variant (Variation ID: 42581). For these reasons, this variant has been classified as Pathogenic. -

Nov 08, 2011

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Met632fs variant has not been reported in the literature. This variant has b een identified by our laboratory in two probands with HCM and has segregated wit h disease in two affected family members. In addition, this variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 632 and leads to a premature stop codon 31 amino acids downstream. Thi s alteration is then predicted to lead to a truncated or absent protein. Loss of function of the MYBPC3 gene is an established disease mechanism in HCM. Therefo re, the Met632fs variant meets our criteria for pathogenicity (http://pcpgm.part ners.org/LMM). -

Cardiomyopathy Pathogenic:1

Feb 09, 2017

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Feb 28, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 27532257, 25611685) -

Computational scores

Source: dbNSFP v4.3

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: rs397515934; hg19: chr11-47362690;