11-47332123-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PP3_Strong

The NM_000256.3(MYBPC3):​c.3763G>A​(p.Ala1255Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000328 in 1,613,512 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1255D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000035 ( 0 hom. )

Consequence

MYBPC3
NM_000256.3 missense

Scores

14
5
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:9B:1

Conservation

PhyloP100: 7.56
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 15 uncertain in NM_000256.3
PP3
MetaRNN computational evidence supports a deleterious effect, 0.94

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MYBPC3NM_000256.3 linkuse as main transcriptc.3763G>A p.Ala1255Thr missense_variant 33/35 ENST00000545968.6

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MYBPC3ENST00000545968.6 linkuse as main transcriptc.3763G>A p.Ala1255Thr missense_variant 33/355 NM_000256.3 P4Q14896-1
MYBPC3ENST00000399249.6 linkuse as main transcriptc.3763G>A p.Ala1255Thr missense_variant 32/345 A2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152252
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000683
AC:
17
AN:
248930
Hom.:
0
AF XY:
0.0000740
AC XY:
10
AN XY:
135088
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000261
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000709
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000349
AC:
51
AN:
1461260
Hom.:
0
Cov.:
33
AF XY:
0.0000316
AC XY:
23
AN XY:
726918
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000268
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:
0.0000333
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152252
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74386
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000654
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000526
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000744
AC:
9
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:9Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
Uncertain significance, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenJan 01, 2017- -
Uncertain significance, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesNov 17, 2023The MYBPC3 c.3763G>A; p.Ala1255Thr variant (rs727503167) is reported in the literature in numerous individuals affected with hypertrophic cardiomyopathy, including one individual with a pathogenic variant in trans in the same gene (Coppini 2014, Field 2022, Lopes 2013, Mademont-Soler 2017, Richard 2003). This variant has also been seen in one individual with dilated cardiomyopathy with a truncating variant in a different gene (Janin 2017). This variant is found in the general population with an overall allele frequency of 0.007% (19/280,328 alleles) in the Genome Aggregation Database (v2.1.1). An in vitro minigene assay demonstrates this variant does not affect splicing (Ito 2017). However computational analyses predict that this variant is deleterious (REVEL: 0.84). Due to conflicting information, the clinical significance of this variant is uncertain at this time. References: Coppini R et al. Clinical phenotype and outcome of hypertrophic cardiomyopathy associated with thin-filament gene mutations. J Am Coll Cardiol. 2014 Dec 23;64(24):2589-2600. PMID: 25524337. Field E et al. Cardiac myosin binding protein-C variants in paediatric-onset hypertrophic cardiomyopathy: natural history and clinical outcomes. J Med Genet. 2022 Aug;59(8):768-775. PMID: 34400558. Ito K et al. Identification of pathogenic gene mutations in LMNA and MYBPC3 that alter RNA splicing. Proc Natl Acad Sci U S A. 2017 Jul 18;114(29):7689-7694. PMID: 28679633. Janin A et al. Truncating mutations on myofibrillar myopathies causing genes as prevalent molecular explanations on patients with dilated cardiomyopathy. Clin Genet. 2017 Dec;92(6):616-623. PMID: 28436997. Lopes LR et al. Genetic complexity in hypertrophic cardiomyopathy revealed by high-throughput sequencing. J Med Genet. 2013 Apr;50(4):228-39. PMID: 23396983. Mademont-Soler I et al. Additional value of screening for minor genes and copy number variants in hypertrophic cardiomyopathy. PLoS One. 2017 Aug 3;12(8):e0181465. PMID: 28771489. Richard P et al. Hypertrophic cardiomyopathy: distribution of disease genes, spectrum of mutations, and implications for a molecular diagnosis strategy. Circulation. 2003 May 6;107(17):2227-32. PMID: 12707239. -
Uncertain significance, criteria provided, single submitterclinical testingGeneDxMar 20, 2024Identified in a 31-year-old female with familial dilated cardiomyopathy (DCM); however, this individual also harbored a truncating FLNC variant (PMID: 28436997); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 25524337, 28840316, 24793961, 27532257, 12707239, 23396983, 28436997, 15115610, 28679633, 28771489, 25351510, 20031618, 28518168, Komissarova2021[article], Komissarova2022[article], 34400558, 37652022, 33782553) -
Cardiomyopathy Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioMay 12, 2022- -
Uncertain significance, criteria provided, single submitterclinical testingColor Diagnostics, LLC DBA Color HealthFeb 06, 2023This missense variant replaces alanine with threonine at codon 1255 of the MYBPC3 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). A minigene assay suggests that this variant does not affect normal RNA splicing (PMID: 28679633), however the clinical relevance of this observation is unknown. This variant has been reported in individuals affected with hypertrophic cardiomyopathy (PMID: 12707239, 20031618, 23396983, 25524337, 25351510, 27532257, 28771489, 33782553). It has also been reported in an individual affected with dilated cardiomyopathy (PMID: 28436997) and in an individual affected with sudden cardiac arrest (doi:10.1101/2022.10.27.22281332). This variant has been identified in 19/280328 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. -
Hypertrophic cardiomyopathy Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 24, 2024This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1255 of the MYBPC3 protein (p.Ala1255Thr). This variant is present in population databases (rs727503167, gnomAD 0.03%), and has an allele count higher than expected for a pathogenic variant. This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 12707239, 20031618, 23396983, 25351510, 25524337, 27532257, 33782553, 34400558). ClinVar contains an entry for this variant (Variation ID: 164023). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -
Uncertain significance, criteria provided, single submitterclinical testingAll of Us Research Program, National Institutes of HealthDec 13, 2023This missense variant replaces alanine with threonine at codon 1255 of the MYBPC3 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). A minigene assay suggests that this variant does not affect normal RNA splicing (PMID: 28679633), however the clinical relevance of this observation is unknown. This variant has been reported in individuals affected with hypertrophic cardiomyopathy (PMID: 12707239, 20031618, 23396983, 25524337, 25351510, 27532257, 28771489, 33782553). It has also been reported in an individual affected with dilated cardiomyopathy (PMID: 28436997) and in an individual affected with sudden cardiac arrest (doi:10.1101/2022.10.27.22281332). This variant has been identified in 19/280328 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. -
Primary familial hypertrophic cardiomyopathy Pathogenic:1
Likely pathogenic, flagged submissionclinical testingBlueprint GeneticsNov 02, 2015- -
not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineAug 02, 2019The p.Ala1255Thr variant in MYBPC3 has been identified in 7 individuals with hypertrophic cardiomyopathy, including one individual who also carried a heterozygous, likely pathogenic variant in another gene (Richard 2003, Lopes 2013, Coppini 2014, Walsh 2017, LMM data). It was also reported in 1 individual with DCM who also carried a frameshift variant in FLNC (Janin 2017). It has been identified in 0.028% (10/35350) of Latino chromosomes by gnomAD (http://gnomad.broadinstitute.org) and reported in ClinVar (Variation ID# 164023). Computational prediction tools and conservation analysis suggest that the p.Ala1255Thr variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: BS1_Supporting, PP3. -
Hypertrophic cardiomyopathy 4 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingMendelicsMay 28, 2019- -
Cardiovascular phenotype Benign:1
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsOct 11, 2021This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.78
CardioboostCm
Uncertain
0.23
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Pathogenic
0.42
CADD
Pathogenic
26
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.84
D;T;T
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.82
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.94
D;D;D
M_CAP
Pathogenic
0.59
D
MetaRNN
Pathogenic
0.94
D;D;D
MetaSVM
Pathogenic
0.84
D
MutationAssessor
Pathogenic
3.7
H;.;.
MutationTaster
Benign
1.0
D;D;D
PrimateAI
Uncertain
0.58
T
PROVEAN
Uncertain
-3.6
D;.;D
REVEL
Pathogenic
0.84
Sift
Pathogenic
0.0
D;.;D
Sift4G
Pathogenic
0.0
D;D;D
Vest4
0.98
MVP
0.93
MPC
0.81
ClinPred
0.98
D
GERP RS
5.5
Varity_R
0.91
gMVP
0.98

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.080
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs727503167; hg19: chr11-47353674; API