Genetic Variant MYBPC3:p.His831SerfsTer2 (chr11-47337502-G-GA) – ACMG Classification: Pathogenic (16 pts)

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000256.3(MYBPC3):c.2490dupT(p.His831SerfsTer2) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,888 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

MYBPC3
NM_000256.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 0.0200

Variant links:

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]

MYBPC3 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 11-47337502-G-GA is Pathogenic according to our data. Variant chr11-47337502-G-GA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 42625.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYBPC3	NM_000256.3 link	c.2490dupT	p.His831SerfsTer2	frameshift_variant	Exon 25 of 35	ENST00000545968.6	NP_000247.2	Q14896-1A5YM48

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
MYBPC3	ENST00000545968.6 link	c.2490dupT	p.His831SerfsTer2	frameshift_variant	Exon 25 of 35	5	NM_000256.3	ENSP00000442795.1	Q14896-1
MYBPC3	ENST00000399249.6 link	c.2490dupT	p.His831SerfsTer2	frameshift_variant	Exon 24 of 34	5		ENSP00000382193.2	A8MXZ9
MYBPC3	ENST00000544791.1 link	n.2422dupT		non_coding_transcript_exon_variant	Exon 25 of 27	5		ENSP00000444259.1	F5GZR4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

249168

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135156

show subpopulations

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:

0.0000266

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461678

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727128

show subpopulations

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:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74368

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

May 27, 2016

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: provider interpretation

c.2490dupT (p.His831Serfs*2) in the MYBPC3 gene Given the fact that this is a loss of function variant in a gene where loss of function is a well-established mechanism of disease and a moderate amount of case data, we consider this variant to be likely pathogenic and we do feel it is suitable for assessing risk in healthy relatives ("predictive genetic testing"). We have seen the variant in an individual with HCM. The variant has been seen in at least 3 unrelated cases of HCM (not including this patient's family). This is moderate case data. It has been reported in 2 cases in the literature. Van Driest et al., 2004 reported the variant using alternative nomenclature (S830 fs/1) in a patient with HCM. Maron et al., 2012 reported the variant in a series of compound heterozygote patients. The patient had HCM and this variant as well as a MYH7 Arg1832Cys variant. This frameshift variant is expected to result in a truncated or absent protein product because of nonsense mediated mRNA decay. Loss of function is an established mechanism of disease in the MYBPC3 gene. The variant was reported online in 3 of 60,340 individuals in the Exome Aggregation Consortium dataset (http://exac.broadinstitute.org/), which currently includes variant calls on ~64,000 individuals of European, African, Latino and Asian descent (as of 5/26/16). Specifically, the variant was observed in 3 of 33,340 non-Finnish European people. The phenotype of those individuals is not publicly available. The dataset is comprised of multiple cohorts, some of which were recruited from the general population, others were enriched for common cardiovascular disease. Note that other variants with strong evidence for pathogenicity have been seen at similar frequencies in datasets like this so this does not necessarily rule out pathogenicity (Pan et al 2012). -

Nov 11, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Also known as c.2490_2491insT and S830 fs/1; 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: 21839045, 24510615, 29237689, 27532257, 33673806, 31980526, 33190526, 37652022, 35653365, 34542152, 15519027) -

Aug 18, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2, PS4_moderate, PVS1 -

Nov 20, 2018

Blueprint Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hypertrophic cardiomyopathy

Pathogenic:3

Dec 12, 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.His831Serfs*2) 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 present in population databases (rs397515966, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 15519027, 21839045). ClinVar contains an entry for this variant (Variation ID: 42625). For these reasons, this variant has been classified as Pathogenic. -

Dec 16, 2019

Clinical Genetics Laboratory, Skane University Hospital Lund

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG criteria met: PVS1, PS4 -

Feb 04, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.His831fs variant in MYBPC3 has been observed in at least 4 individuals wit h HCM (Van Driest 2004, Kapplinger 2014, LMM unpublished data) and segregated wi th disease in 1 affected relative (LMM unpublished data). This variant has also been identified in 3/66680 of European chromosomes by the Exome Aggregation Cons ortium (ExAC, http://exac.broadinstitute.org; dbSNP rs397515966). Please note th at for diseases with clinical variability and reduced penetrance, pathogenic var iants may be present at a low frequency in the general population. This variant is predicted to cause a frameshift, which alters the protein?s amino acid sequen ce beginning at position 831 and leads to a premature termination codon 2 amino acids downstream. This alteration is then predicted to lead to a truncated or ab sent protein. Heterozygous loss of function of function of the MYBPC3 gene is an established disease mechanism in HCM. In summary, this variant meets our criter ia to be classified as pathogenic for HCM in an autosomal dominant manner (http: //www.partners.org/personalizedmedicine/LMM) based on the predicted impact of th e variant. -

Hypertrophic cardiomyopathy 4

Pathogenic:1

Apr 04, 2022

Clinical Genetics Laboratory, Region Ostergotland

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1, PS4, PP5 -

Primary familial hypertrophic cardiomyopathy

Pathogenic:1

Oct 01, 2018

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MYBPC3 c.2490dupT (p.His831SerfsX2) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.2e-05 in 246844 control chromosomes. c.2490dupT has been reported in the literature in multiple individuals affected with Hypertrophic Cardiomyopathy (VanDriest 2004 Maron 2012, Kapplinger 2014, Walsh 2017). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic (3x) / likely pathogenic (1x). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over