chr14-23415794-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP2

The NM_000257.4(MYH7):​c.4992C>A​(p.Asn1664Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. N1664S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

MYH7
NM_000257.4 missense

Scores

2
5
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:5

Conservation

PhyloP100: -3.27

Publications

1 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]
MHRT (HGNC:51291): (myosin heavy chain associated RNA transcript) This gene encodes a spliced long non-coding RNA that may act as a cardioprotective agent in the heart. Based on a study of a similar gene in mouse, the encoded transcript may regulate chromatin remodeling by acting as a decoy to the BRG1 chromatin repressor complex thus preventing it from binding to its genomic targets. Blocking the actions of BRG1 could be crucial in protecting the heart from pathological hypertrophy. [provided by RefSeq, Dec 2014]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PM2
Very rare variant in population databases, with high coverage;
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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYH7NM_000257.4 linkc.4992C>A p.Asn1664Lys missense_variant Exon 35 of 40 ENST00000355349.4 NP_000248.2 P12883
MYH7NM_001407004.1 linkc.4992C>A p.Asn1664Lys missense_variant Exon 34 of 39 NP_001393933.1
MHRTNR_126491.1 linkn.226G>T non_coding_transcript_exon_variant Exon 2 of 6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MYH7ENST00000355349.4 linkc.4992C>A p.Asn1664Lys missense_variant Exon 35 of 40 1 NM_000257.4 ENSP00000347507.3 P12883
MYH7ENST00000713768.1 linkc.4992C>A p.Asn1664Lys missense_variant Exon 35 of 41 ENSP00000519070.1
MYH7ENST00000713769.1 linkc.4992C>A p.Asn1664Lys missense_variant Exon 34 of 39 ENSP00000519071.1
ENSG00000258444ENST00000557368.1 linkn.*108G>T downstream_gene_variant 3

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251434
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1461894
Hom.:
0
Cov.:
34
AF XY:
0.00000275
AC XY:
2
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
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:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hypertrophic cardiomyopathy 1 Pathogenic:1Uncertain:1
-
Laboratory of Genetics and Molecular Cardiology, University of São Paulo
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 28, 2019
Mendelics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Uncertain:1
Apr 09, 2019
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces asparagine with lysine at codon 1664 of the MYH7 protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant. This variant has been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 27247418). This variant has also been identified in 3/251434 chromosomes in the general population by the Genome Aggregation Database (gnomAD). 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. -

not provided Uncertain:1
Oct 29, 2020
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hypertrophic cardiomyopathy Uncertain:1
Dec 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 1664 of the MYH7 protein (p.Asn1664Lys). This variant is present in population databases (rs763538103, gnomAD 0.003%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 27247418). ClinVar contains an entry for this variant (Variation ID: 217461). An algorithm developed specifically for the MYH7 gene suggests that this missense change is likely to be tolerated (PMID: 21310275). 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. -

MYH7-related disorder Uncertain:1
Feb 19, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The MYH7 c.4992C>A variant is predicted to result in the amino acid substitution p.Asn1664Lys. This variant has been reported in an individual with hypertrophic cardiomyopathy (Table S1, Homburger et al. 2016. PubMed ID: 27247418). This variant is reported in 0.0029% of alleles in individuals of Latino descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.31
CardioboostCm
Benign
0.081
BayesDel_addAF
Benign
-0.14
T
BayesDel_noAF
Benign
-0.36
CADD
Benign
14
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.53
D
Eigen
Benign
-0.33
Eigen_PC
Benign
-0.45
FATHMM_MKL
Benign
0.11
N
LIST_S2
Benign
0.81
T
M_CAP
Pathogenic
0.93
D
MetaRNN
Uncertain
0.68
D
MetaSVM
Uncertain
-0.24
T
MutationAssessor
Benign
1.9
L
PhyloP100
-3.3
PrimateAI
Pathogenic
0.86
D
PROVEAN
Benign
-1.3
N
REVEL
Uncertain
0.38
Sift
Benign
0.042
D
Sift4G
Benign
0.47
T
Polyphen
1.0
D
Vest4
0.83
MutPred
0.46
Gain of ubiquitination at N1664 (P = 0.017);
MVP
0.93
MPC
1.2
ClinPred
0.22
T
GERP RS
0.79
Varity_R
0.27
gMVP
0.72
Mutation Taster
=19/81
disease causing (ClinVar)

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: rs763538103; hg19: chr14-23885003; API