14-23415766-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PP2PP3_Moderate
The NM_000257.4(MYH7):c.5020G>A(p.Val1674Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000991 in 1,614,090 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. V1674L) has been classified as Uncertain significance.
Frequency
Consequence
NM_000257.4 missense
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Uncertain_significance. The variant received 5 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MYH7 | NM_000257.4 | c.5020G>A | p.Val1674Met | missense_variant | Exon 35 of 40 | ENST00000355349.4 | NP_000248.2 | |
| MYH7 | NM_001407004.1 | c.5020G>A | p.Val1674Met | missense_variant | Exon 34 of 39 | NP_001393933.1 | ||
| MHRT | NR_126491.1 | n.198C>T | non_coding_transcript_exon_variant | Exon 2 of 6 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MYH7 | ENST00000355349.4 | c.5020G>A | p.Val1674Met | missense_variant | Exon 35 of 40 | 1 | NM_000257.4 | ENSP00000347507.3 | ||
| MYH7 | ENST00000713768.1 | c.5020G>A | p.Val1674Met | missense_variant | Exon 35 of 41 | ENSP00000519070.1 | ||||
| MYH7 | ENST00000713769.1 | c.5020G>A | p.Val1674Met | missense_variant | Exon 34 of 39 | ENSP00000519071.1 | ||||
| ENSG00000258444 | ENST00000557368.1 | n.*80C>T | downstream_gene_variant | 3 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152196Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000119 AC: 3AN: 251412 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000889 AC: 13AN: 1461894Hom.: 0 Cov.: 34 AF XY: 0.0000110 AC XY: 8AN XY: 727248 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152196Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74352 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Cardiomyopathy Uncertain:2
This missense variant replaces valine with methionine at codon 1674 of the MYH7 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 been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 27532257, 25611685). This variant has been identified in 3/251412 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. -
This missense variant replaces valine with methionine at codon 1674 of the MYH7 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 been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 27532257, 25611685). This variant has been identified in 3/251412 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
This sequence change in MYH7 is predicted to replace valine with methionine at codon 1674, p.(Val1674Met). The valine residue is highly conserved (100 vertebrates, Multiz Alignments), and is located in the myosin tail domain. There is a small physicochemical difference between valine and methionine. The highest population minor allele frequency in the population database gnomAD v4.0 is 0.002% (2/91,086 alleles) in the South Asian population, which is consistent with hypertrophic cardiomyopathy. This variant has been reported in at least one individual with hypertrophic cardiomyopathy (PMID: 27532257). This variant has been observed in an individual with a pathogenic variant in MYBPC3 (Royal Melbourne Hospital). Computational evidence is uninformative for the missense substitution (REVEL = 0.498). Based on the classification scheme RMH Modified ACMG/AMP Guidelines v1.6.1, this variant is classified as a VARIANT OF UNCERTAIN SIGNIFICANCE. Following criteria are met: PM2_Supporting. -
This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1674 of the MYH7 protein (p.Val1674Met). This variant is present in population databases (rs397516235, gnomAD 0.006%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 25611685, 27532257, 37652022). ClinVar contains an entry for this variant (Variation ID: 43052). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MYH7 protein function with a positive predictive value of 95%. 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. -
not specified Uncertain:1
The Val1674Met variant in MYH7 has not been reported in the literature, but has been identified in 1 individual with HCM (this individual) out of >3600 probands (>2200 Caucasian) tested by our laboratory. In addition, this variant has not b een identified in large and broad populations (European and African American) se quenced by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS) . While this low frequency supports a pathogenic role, the ethnicity of this ind ividual was not specified and it remains possible that this variant is common in other populations. Valine (Val) at position 1674 is highly conserved in mammal and across evolutionarily distant species, though the change to methionine (Met) was predicted to be benign using a computational tool, which was validated by o ur laboratory using a set of cardiomyopathy variants with well-established clini cal significance (benign predictions are estimated to be correct 89% of the time , Jordan 2011). Additional studies are needed to fully assess the clinical signi ficance of this variant. -
Dilated cardiomyopathy 1S Uncertain:1
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0105 - The mechanism of disease for this gene is not clearly established; however, missense variants have been proposed to act in a dominant negative manner (PMID: 24714796). (I) 0108 - This gene is associated with both recessive and dominant disease. Disease associated with this gene usually has autosomal dominant inheritance; however, a recessive inheritance pattern has been observed in severe cases (OMIM). (I) 0112 - The condition associated with this gene has incomplete penetrance (PMID: 29300372). (I) 0200 - Variant is predicted to result in a missense amino acid change from valine to methionine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD <0.01 (v2+v3: 6 heterozygotes, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (1 heterozygote, 0 homozygotes). (I) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0600 - Variant is located in the annotated myosin tail domain (DECIPHER). (I) 0710 - Another variant comparable to the one identified in this case has inconclusive previous evidence for pathogenicity. p.(Val1674Leu) is reported in ClinVar four times as a variant of unknown significance (VUS). It has also been identified in an individual with dilated cardiomyopathy and classified in this instance as a VUS (PMID: 27532257). (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. This variant has been reported three times in ClinVar as a VUS and in two individuals with hypertrophic cardiomyopathy; however, it was classified as a VUS (PMID: 27532257, ClinVar). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at