11-47349899-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PM5

The NM_000256.3(MYBPC3):c.529C>G(p.Arg177Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000344 in 1,455,282 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R177C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MYBPC3 NM_000256.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.75

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 Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-47349899-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYBPC3	NM_000256.3	c.529C>G	p.Arg177Gly	missense_variant	5/35	ENST00000545968.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYBPC3	ENST00000545968.6	c.529C>G	p.Arg177Gly	missense_variant	5/35	5	NM_000256.3	P4
MYBPC3	ENST00000399249.6	c.529C>G	p.Arg177Gly	missense_variant	5/34	5		A2
MYBPC3	ENST00000544791.1	c.529C>G	p.Arg177Gly	missense_variant, NMD_transcript_variant	5/27	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000344 AC: 5 AN: 1455282 Hom.: 0 Cov.: 31 AF XY: 0.00000415 AC XY: 3 AN XY: 723300

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: 0.00000451

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Feb 13, 2020

This missense variant replaces arginine with glycine at codon 177 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 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.52
CardioboostCm	Benign	0.017
BayesDel_addAF	Uncertain	0.027	T
BayesDel_noAF	Benign	-0.20
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.61	D;T;T
Eigen	Uncertain	0.23
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Uncertain	0.65	D;D;D
MetaSVM	Benign	-0.42	T
MutationAssessor	Benign	1.4	L;.;.
MutationTaster	Benign	0.95	D;D;D
PrimateAI	Benign	0.37	T
PROVEAN	Uncertain	-3.9	D;D;D
REVEL	Uncertain	0.30
Sift	Uncertain	0.0040	D;D;D
Sift4G	Uncertain	0.0030	D;D;D
Polyphen		0.34	B;.;.
Vest4		0.55
MutPred		0.72		Loss of stability (P = 0.0289);Loss of stability (P = 0.0289);Loss of stability (P = 0.0289);
MVP		0.87
MPC		0.61
ClinPred		0.97	D
GERP RS		4.8
Varity_R		0.42
gMVP		0.81

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

Other links and lift over

dbSNP: rs193922385; hg19: chr11-47371450;