rs1555120639

Positions:

• chr11-47333922-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP5

The NM_000256.3(MYBPC3):​c.2994G>A​(p.Gln998=) variant causes a splice region, synonymous change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000127 in 1,570,344 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: MYBPC3 NM_000256.3 splice_region, synonymous
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.52

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-47333922-C-T is Pathogenic according to our data. Variant chr11-47333922-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 523711.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYBPC3	NM_000256.3	c.2994G>A	p.Gln998=	splice_region_variant, synonymous_variant	28/35	ENST00000545968.6	NP_000247.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYBPC3	ENST00000545968.6	c.2994G>A	p.Gln998=	splice_region_variant, synonymous_variant	28/35	5	NM_000256.3	ENSP00000442795	P4
MYBPC3	ENST00000399249.6	c.2994G>A	p.Gln998=	splice_region_variant, synonymous_variant	27/34	5		ENSP00000382193	A2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 7.05e-7 AC: 1 AN: 1418102 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 701382

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000264

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74382

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Mar 01, 2017

- -

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 07, 2018

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has not been reported in the literature in individuals with MYBPC3-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change affects codon 998 of the MYBPC3 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the MYBPC3 protein. This variant also falls at the last nucleotide of exon 28 of the MYBPC3 coding sequence, which is part of the consensus splice site for this exon. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.27
CADD	Uncertain	24
DANN	Benign	0.93

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.97
SpliceAI score (max)		0.78		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.57		Position offset: 36
DS_DL_spliceai		0.78		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555120639; hg19: chr11-47355473;