NM_000256.3:c.999C>A

Variant names:

• chr11-47346298-G-T
• rs367947846
• NM_000256.3:c.999C>A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000256.3(MYBPC3):​c.999C>A​(p.Tyr333*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Y333Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYBPC3 NM_000256.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: -0.704

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-47346298-G-T is Pathogenic according to our data. Variant chr11-47346298-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 960010.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	c.999C>A	p.Tyr333*	stop_gained	Exon 12 of 35	ENST00000545968.6	NP_000247.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYBPC3	ENST00000545968.6	c.999C>A	p.Tyr333*	stop_gained	Exon 12 of 35	5	NM_000256.3	ENSP00000442795.1
MYBPC3	ENST00000399249.6	c.999C>A	p.Tyr333*	stop_gained	Exon 11 of 34	5		ENSP00000382193.2
MYBPC3	ENST00000544791.1	n.999C>A		non_coding_transcript_exon_variant	Exon 12 of 27	5		ENSP00000444259.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Jun 17, 2019

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1, PM2 -

Jul 13, 2022

Clinical Genetics Laboratory, Skane University Hospital Lund

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Left ventricular noncompaction 10 Pathogenic:1

Jan 01, 2019

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hypertrophic cardiomyopathy Pathogenic:1

Oct 04, 2023

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.Tyr333*) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 23233322). ClinVar contains an entry for this variant (Variation ID: 960010). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Benign	-0.052
Eigen_PC	Benign	-0.38
FATHMM_MKL	Benign	0.27	N
Vest4		0.74
GERP RS		-5.4

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		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: rs367947846; hg19: chr11-47367849;