11-47338649-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000256.3(MYBPC3):c.2179G>C(p.Val727Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. V727M) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYBPC3 NM_000256.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.85

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.

• PM1: In a domain Ig-like C2-type 5 (size 126) in uniprot entity MYPC3_HUMAN there are 50 pathogenic changes around while only 6 benign (89%) in NM_000256.3
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYBPC3	NM_000256.3	c.2179G>C	p.Val727Leu	missense_variant	23/35	ENST00000545968.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYBPC3	ENST00000545968.6	c.2179G>C	p.Val727Leu	missense_variant	23/35	5	NM_000256.3	P4
MYBPC3	ENST00000399249.6	c.2179G>C	p.Val727Leu	missense_variant	22/34	5		A2
MYBPC3	ENST00000544791.1	c.2179G>C	p.Val727Leu	missense_variant, NMD_transcript_variant	23/27	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

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

Dec 05, 2023

This missense variant replaces valine with leucine at codon 727 of the MYBPC3 protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant 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). 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	0.51
CardioboostCm	Benign	0.055
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Benign	0.25	T;T;T
Eigen	Benign	0.045
Eigen_PC	Benign	0.22
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.81	T;T;T
M_CAP	Uncertain	0.15	D
MetaRNN	Uncertain	0.67	D;D;D
MetaSVM	Benign	-0.77	T
MutationAssessor	Benign	1.5	L;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-1.8	N;.;N
REVEL	Benign	0.23
Sift	Benign	0.17	T;.;T
Sift4G	Benign	0.097	T;T;T
Vest4		0.73
MVP		0.86
MPC		0.65
ClinPred		0.95	D
GERP RS		5.4
Varity_R		0.21
gMVP		0.67

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: rs564378953; hg19: chr11-47360200;