Genetic Variant MYBPC3:p.Val840Met (chr11-47337475-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM1

The NM_000256.3(MYBPC3):c.2518G>A(p.Val840Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000123 in 1,461,574 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

MYBPC3
NM_000256.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 4.70

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1

In a domain Fibronectin type-III 1 (size 96) in uniprot entity MYPC3_HUMAN there are 31 pathogenic changes around while only 3 benign (91%) in NM_000256.3

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYBPC3	NM_000256.3 link	c.2518G>A	p.Val840Met	missense_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.2518G>A	p.Val840Met	missense_variant	Exon 25 of 35	5	NM_000256.3	ENSP00000442795.1	Q14896-1
MYBPC3	ENST00000399249.6 link	c.2518G>A	p.Val840Met	missense_variant	Exon 24 of 34	5		ENSP00000382193.2	A8MXZ9
MYBPC3	ENST00000544791.1 link	n.*23G>A		non_coding_transcript_exon_variant	Exon 25 of 27	5		ENSP00000444259.1	F5GZR4
MYBPC3	ENST00000544791.1 link	n.*23G>A		3_prime_UTR_variant	Exon 25 of 27	5		ENSP00000444259.1	F5GZR4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000121

AC:

AN:

248830

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

134974

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:

0.0000123

AC:

AN:

1461574

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727074

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000126

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000227

ESP6500AA

AF:

0.000231

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hypertrophic cardiomyopathy

Uncertain:2

May 04, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces valine with methionine at codon 840 of the MYBPC3 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 27532257). This variant has also been identified in 5/280216 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Feb 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 840 of the MYBPC3 protein (p.Val840Met). This variant is present in population databases (rs376936056, gnomAD 0.004%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 27532257). ClinVar contains an entry for this variant (Variation ID: 42631). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

not specified

Uncertain:1

May 26, 2010

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Val840Met has not been reported in the literature, and it also has not been identified in >1000 caucasian probands tested by this laboratory. However, Alig nGVGD and PolyPhen predict the variant is benign, while SIFT predicts that the v ariant is not tolerated. -

Cardiomyopathy

Uncertain:1

Mar 23, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces valine with methionine at codon 840 of the MYBPC3 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 25611685, 27532257). This variant has been identified in 5/280216 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not provided

Uncertain:1

Aug 01, 2017

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A variant of uncertain significance has been identified in the MYBPC3 gene. The V840M variant has not published in a patient with HCM (Walsh et al., 2017); however, additional clinical details and segregation information were not provided. The V840M variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. Nevertheless, the V840M variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). Finally, this substitution occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. -

Cardiovascular phenotype

Uncertain:1

Dec 21, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2518G>A (p.V840M) alteration is located in exon 25 (coding exon 25) of the MYBPC3 gene. This alteration results from a G to A substitution at nucleotide position 2518, causing the valine (V) at amino acid position 840 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.36

CardioboostCm

Uncertain

0.23

BayesDel_addAF

Benign

-0.033

BayesDel_noAF

Benign

-0.22

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.22

T;T;T

Eigen

Uncertain

0.62

Eigen_PC

Uncertain

0.59

FATHMM_MKL

Uncertain

0.89

LIST_S2

Uncertain

0.95

D;D;D

M_CAP

Uncertain

0.19

MetaRNN

Uncertain

0.50

T;T;T

MetaSVM

Benign

-0.43

MutationAssessor

Benign

1.8

L;.;.

PrimateAI

Uncertain

0.66

PROVEAN

Uncertain

-2.6

D;N;D

REVEL

Benign

0.19

Sift

Uncertain

0.0070

D;T;D

Sift4G

Pathogenic

0.0010

D;D;D

Vest4

0.53

MVP

0.82

MPC

0.73

ClinPred

0.96

GERP RS

4.6

Varity_R

0.31

gMVP

0.44

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