rs1555122453

Variant names:

• chr11-47343587-G-T
• rs1555122453
• NM_000256.3:c.1128C>A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_000256.3(MYBPC3):​c.1128C>A​(p.Ser376Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYBPC3 NM_000256.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.38

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.

• PM1: In a domain Ig-like C2-type 2 (size 90) in uniprot entity MYPC3_HUMAN there are 21 pathogenic changes around while only 3 benign (88%) in NM_000256.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3845085).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYBPC3	NM_000256.3	c.1128C>A	p.Ser376Arg	missense_variant	Exon 13 of 35	ENST00000545968.6	NP_000247.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYBPC3	ENST00000545968.6	c.1128C>A	p.Ser376Arg	missense_variant	Exon 13 of 35	5	NM_000256.3	ENSP00000442795.1
MYBPC3	ENST00000399249.6	c.1128C>A	p.Ser376Arg	missense_variant	Exon 12 of 34	5		ENSP00000382193.2
MYBPC3	ENST00000544791.1	n.1128C>A		non_coding_transcript_exon_variant	Exon 13 of 27	5		ENSP00000444259.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 45

GnomAD4 genome Cov.: 32

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Feb 21, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function -

Hypertrophic cardiomyopathy Uncertain:1

Apr 29, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine with arginine at codon 376 of the MYBPC3 protein (p.Ser376Arg). The serine residue is weakly conserved and there is a moderate physicochemical difference between serine and arginine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a MYBPC3-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.51
CardioboostCm	Benign	0.0094
BayesDel_addAF	Benign	-0.092	T
BayesDel_noAF	Benign	-0.37
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.25	T;T;T
Eigen	Benign	-0.041
Eigen_PC	Benign	0.14
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.95	D;D;D
M_CAP	Uncertain	0.22	D
MetaRNN	Benign	0.38	T;T;T
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	0.47	N;.;.
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-2.1	N;N;N
REVEL	Benign	0.093
Sift	Uncertain	0.0040	D;D;D
Sift4G	Uncertain	0.0020	D;D;D
Polyphen		0.075	B;.;.
Vest4		0.39
MutPred		0.40		Gain of MoRF binding (P = 0.0175);Gain of MoRF binding (P = 0.0175);Gain of MoRF binding (P = 0.0175);
MVP		0.85
MPC		0.25
ClinPred		0.84	D
GERP RS		5.0
Varity_R		0.56
gMVP		0.20

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1555122453; hg19: chr11-47365138;