rs1064796634

chr11-47332078-C-Achr11-47332078-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000256.3(MYBPC3):c.3808G>T(p.Val1270Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000000686 in 1,457,508 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1270G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MYBPC3 NM_000256.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.73

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a domain Ig-like C2-type 7 (size 93) in uniprot entity MYPC3_HUMAN there are 46 pathogenic changes around while only 3 benign (94%) in NM_000256.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.865

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYBPC3	NM_000256.3	c.3808G>T	p.Val1270Leu	missense_variant	33/35	ENST00000545968.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYBPC3	ENST00000545968.6	c.3808G>T	p.Val1270Leu	missense_variant	33/35	5	NM_000256.3	P4
MYBPC3	ENST00000399249.6	c.3808G>T	p.Val1270Leu	missense_variant	32/34	5		A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1457508 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 724466

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: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Dec 16, 2019

This missense variant replaces valine with leucine at codon 1270 of the MYBPC3 protein. Computational prediction tool suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold ≥0.7, 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 not been reported in individuals affected with cardiovascular disorders in the literature. This variant has not been identified 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

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 27, 2017

A variant of uncertain significance has been identified in the MYBPC3 gene. The V1270L variant has not been published as pathogenic or been reported as benign to our knowledge. Additionally, the V1270L variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). 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. However, V1270L is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.74
CardioboostCm	Benign	0.056
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D;T;T
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.87	D;D;D
MetaSVM	Uncertain	0.77	D
MutationAssessor	Uncertain	2.8	M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-2.7	D;.;D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0020	D;.;D
Sift4G	Uncertain	0.0030	D;D;D
Vest4		0.81
MVP		0.96
MPC		0.27
ClinPred		0.98	D
GERP RS		5.5
Varity_R		0.66
gMVP		0.92

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1064796634; hg19: chr11-47353629;