rs780458215

chr11-47350082-G-Achr11-47350082-G-Cchr11-47350082-G-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000256.3(MYBPC3):c.437C>T(p.Thr146Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000071 in 1,408,112 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. 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. T146A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000071 (0 hom.)
• Consequence: MYBPC3 NM_000256.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.203

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 Likely_benign. Variant got -4 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.056915224).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYBPC3	NM_000256.3	c.437C>T	p.Thr146Ile	missense_variant	4/35	ENST00000545968.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYBPC3	ENST00000545968.6	c.437C>T	p.Thr146Ile	missense_variant	4/35	5	NM_000256.3	P4
MYBPC3	ENST00000399249.6	c.437C>T	p.Thr146Ile	missense_variant	4/34	5		A2
MYBPC3	ENST00000544791.1	c.437C>T	p.Thr146Ile	missense_variant, NMD_transcript_variant	4/27	5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000298 AC: 5 AN: 167712 Hom.: 0 AF XY: 0.0000336 AC XY: 3 AN XY: 89280

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000215

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000710 AC: 10 AN: 1408112 Hom.: 0 Cov.: 35 AF XY: 0.0000101 AC XY: 7 AN XY: 695542

Gnomad4 AFR exome AF: 0.0000312

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000100

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000171

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000349 AC: 4

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Jan 11, 2024	This missense variant replaces threonine with isoleucine at codon 146 of the MYBPC3 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 5/167712 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 29, 2022	The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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. 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. ClinVar contains an entry for this variant (Variation ID: 918905). This variant has not been reported in the literature in individuals affected with MYBPC3-related conditions. This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 146 of the MYBPC3 protein (p.Thr146Ile). -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Jan 15, 2020

This missense variant replaces threonine with isoleucine at codon 146 of the MYBPC3 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 5/167712 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The 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	Benign	0.13
CardioboostCm	Benign	0.0029
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.52
Cadd	Benign	7.2
Dann	Benign	0.92
DEOGEN2	Benign	0.17	T;T;T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.0046	N
LIST_S2	Benign	0.52	T;T;T
M_CAP	Benign	0.0060	T
MetaRNN	Benign	0.057	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.0	N;.;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-0.64	N;N;N
REVEL	Benign	0.044
Sift	Benign	0.12	T;T;T
Sift4G	Benign	0.18	T;T;T
Polyphen		0.041	B;.;.
Vest4		0.15
MVP		0.35
MPC		0.24
ClinPred		0.093	T
GERP RS		-4.9
Varity_R		0.034
gMVP		0.16

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: rs780458215; hg19: chr11-47371633;