14-23433131-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP2PP3_Moderate

The NM_000257.4(MYH7):​c.298G>A​(p.Ala100Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,614,118 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A100V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

MYH7
NM_000257.4 missense

Scores

7
9
4

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:5

Conservation

PhyloP100: 2.58

Publications

5 publications found
Variant links:
Genes affected
MYH7 (HGNC:7577): (myosin heavy chain 7) Muscle myosin is a hexameric protein containing 2 heavy chain subunits, 2 alkali light chain subunits, and 2 regulatory light chain subunits. This gene encodes the beta (or slow) heavy chain subunit of cardiac myosin. It is expressed predominantly in normal human ventricle. It is also expressed in skeletal muscle tissues rich in slow-twitch type I muscle fibers. Changes in the relative abundance of this protein and the alpha (or fast) heavy subunit of cardiac myosin correlate with the contractile velocity of cardiac muscle. Its expression is also altered during thyroid hormone depletion and hemodynamic overloading. Mutations in this gene are associated with familial hypertrophic cardiomyopathy, myosin storage myopathy, dilated cardiomyopathy, and Laing distal myopathy. [provided by RefSeq, May 2022]
MYH7 Gene-Disease associations (from GenCC):
  • dilated cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • dilated cardiomyopathy 1S
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • hypertrophic cardiomyopathy 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • MYH7-related skeletal myopathy
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
  • myopathy, myosin storage, autosomal recessive
    Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • myopathy, myosin storage, autosomal dominant
    Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
  • congenital myopathy 7A, myosin storage, autosomal dominant
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Ebstein anomaly
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • hyaline body myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • left ventricular noncompaction
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • arrhythmogenic right ventricular cardiomyopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • congenital heart disease
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PP2
Missense variant in the MYH7 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 341 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. Gene score misZ: 3.9329 (above the threshold of 3.09). Trascript score misZ: 6.7889 (above the threshold of 3.09). GenCC associations: The gene is linked to myopathy, myosin storage, autosomal recessive, MYH7-related skeletal myopathy, congenital myopathy 7A, myosin storage, autosomal dominant, Ebstein anomaly, hyaline body myopathy, left ventricular noncompaction, hypertrophic cardiomyopathy 1, dilated cardiomyopathy 1S, dilated cardiomyopathy, congenital heart disease, familial isolated dilated cardiomyopathy, myopathy, myosin storage, autosomal dominant, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.925

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYH7NM_000257.4 linkc.298G>A p.Ala100Thr missense_variant Exon 4 of 40 ENST00000355349.4 NP_000248.2 P12883
MYH7NM_001407004.1 linkc.298G>A p.Ala100Thr missense_variant Exon 3 of 39 NP_001393933.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MYH7ENST00000355349.4 linkc.298G>A p.Ala100Thr missense_variant Exon 4 of 40 1 NM_000257.4 ENSP00000347507.3 P12883
MYH7ENST00000713768.1 linkc.298G>A p.Ala100Thr missense_variant Exon 4 of 41 ENSP00000519070.1
MYH7ENST00000713769.1 linkc.298G>A p.Ala100Thr missense_variant Exon 3 of 39 ENSP00000519071.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152108
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251476
AF XY:
0.0000147
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000233
AC:
34
AN:
1461892
Hom.:
0
Cov.:
32
AF XY:
0.0000289
AC XY:
21
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000696
AC:
6
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000252
AC:
28
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
3
6
10
13
16
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152226
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74422
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41544
American (AMR)
AF:
0.0000654
AC:
1
AN:
15296
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5162
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67996
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.225
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000138
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cardiomyopathy Uncertain:2
Aug 03, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces alanine with threonine at codon 100 of the MYH7 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with dilated cardiomyopathy (PMID: 26084686). It has also been reported in two unrelated individuals affected with hypertrophic cardiomyopathy who both carried additional pathogenic variants (PMID: 22765922, 23396983, 23870641, 25351510, 26654849, 27532257, 28356264). This variant has been identified in 4/251476 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. -

Sep 17, 2023
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces alanine with threonine at codon 100 of the MYH7 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with dilated cardiomyopathy (PMID: 26084686). It has also been reported in two unrelated individuals affected with hypertrophic cardiomyopathy who both carried additional pathogenic variants (PMID: 22765922, 23396983, 23870641, 25351510, 26654849, 27532257, 28356264). This variant has been identified in 4/251476 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. -

Restrictive cardiomyopathy Pathogenic:1
Jul 03, 2014
Blueprint Genetics
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not specified Uncertain:1
Oct 20, 2016
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: Reported in 1 HCM proband (PMID 22765922), 1 Finnish DCM proband (PMID 26084686); No segregation data; ClinVar: LP by Blueprint -

Hypertrophic cardiomyopathy Uncertain:1
Mar 12, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 100 of the MYH7 protein (p.Ala100Thr). This variant is present in population databases (rs730880154, gnomAD 0.003%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 22765922, 27532257). ClinVar contains an entry for this variant (Variation ID: 180430). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Cardiovascular phenotype Uncertain:1
Feb 21, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A100T variant (also known as c.298G>A), located in coding exon 2 of the MYH7 gene, results from a G to A substitution at nucleotide position 298. The alanine at codon 100 is replaced by threonine, an amino acid with similar properties. This variant has been detected in hypertrophic cardiomyopathy cohorts; however, case reports may overlap and some individuals also had mutations other cardiomyopathy-related genes (Coto E et al. J Mol Diagn, 2012 Sep;14:518-24; Reguero JR et al. Int J Cardiol, 2013 Oct;168:4555-6; Lopes LR et al. J Med Genet, 2013 Apr;50:228-39; Lopes LR et al. Heart, 2015 Feb;101:294-301; G&oacute;mez J et al. Rev Esp Cardiol (Engl Ed), 2016 Jan;69:61-8; Walsh R et al. Genet Med, 2017 02;19:192-203). This variant has also been detected in an individual from a dilated cardiomyopathy cohort; however, details were limited (Akinrinade O et al. Eur Heart J, 2015 Sep;36:2327-37). This alteration was also noted in a biobank cohort (Park J et al. Hum Mol Genet, 2022 Mar;31:827-837). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.82
CardioboostCm
Pathogenic
0.94
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.15
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.76
D
Eigen
Uncertain
0.21
Eigen_PC
Benign
0.14
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Uncertain
0.91
D
M_CAP
Pathogenic
0.94
D
MetaRNN
Pathogenic
0.93
D
MetaSVM
Uncertain
0.44
D
MutationAssessor
Benign
0.70
N
PhyloP100
2.6
PrimateAI
Uncertain
0.77
T
PROVEAN
Benign
-1.7
N
REVEL
Pathogenic
0.69
Sift
Uncertain
0.013
D
Sift4G
Uncertain
0.026
D
Polyphen
0.95
P
Vest4
0.88
MVP
0.90
MPC
2.1
ClinPred
0.76
D
GERP RS
3.8
Varity_R
0.42
gMVP
0.83
Mutation Taster
=7/93
disease causing

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

Other links and lift over

dbSNP: rs730880154; hg19: chr14-23902340; COSMIC: COSV62522404; API