rs1555123438

Positions:

• chr11-47349921-A-ACCTG

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000256.3(MYBPC3):​c.506-3_506dupCAGG​(p.Gly170fs) variant causes a frameshift, splice region change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYBPC3 NM_000256.3 frameshift, splice_region
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.09

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 12 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 11-47349921-A-ACCTG is Pathogenic according to our data. Variant chr11-47349921-A-ACCTG is described in ClinVar as [Pathogenic]. Clinvar id is 454332.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYBPC3	NM_000256.3	c.506-3_506dupCAGG	p.Gly170fs	frameshift_variant, splice_region_variant	5/35	ENST00000545968.6	NP_000247.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYBPC3	ENST00000545968.6	c.506-3_506dupCAGG	p.Gly170fs	frameshift_variant, splice_region_variant	5/35	5	NM_000256.3	ENSP00000442795.1
MYBPC3	ENST00000399249.6	c.506-3_506dupCAGG	p.Gly170fs	frameshift_variant, splice_region_variant	5/34	5		ENSP00000382193.2
MYBPC3	ENST00000544791.1	n.506-3_506dupCAGG		splice_region_variant, non_coding_transcript_exon_variant	5/27	5		ENSP00000444259.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 15, 2020

This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Gly170Argfs*72) in the MYBPC3 gene. It is expected to result in an absent or disrupted protein product. This variant has not been reported in the literature in individuals with MYBPC3-related conditions. ClinVar contains an entry for this variant (Variation ID: 454332). For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in MYBPC3 are known to be pathogenic (PMID: 19574547). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555123438; hg19: chr11-47371472;