chr14-23417202-C-G

Variant names:

• chr14-23417202-C-G
• rs730880911
• NM_000257.4:c.4470G>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PS4_Supporting PM2

This summary comes from the ClinGen Evidence Repository: The NM_000257.4(MYH7):c.4470G>C (p.Glu1490Asp) variant has been reported in 2 individuals with HCM (PS4_Supporting; GeneDx pers. comm., LMM pers. comm.). This variant was absent from large population studies (PM2; gnomAD v.2.1.1, http://gnomad.broadinstitute.org). Computational prediction tools and conservation analysis do not provide strong support for or against an impact to the protein. In summary, due to insufficient evidence, this variant is classified as uncertain significance for hypertrophic cardiomyopathy in an autosomal dominant manner. MYH7-specific ACMG/AMP criteria applied (PMID:29300372): PS4_Supporting, PM2. LINK:https://erepo.genome.network/evrepo/ui/classification/CA015001/MONDO:0005045/002

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 0.469

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.4470G>C	p.Glu1490Asp	missense_variant	Exon 32 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.4470G>C	p.Glu1490Asp	missense_variant	Exon 31 of 39		NP_001393933.1
MHRT	NR_126491.1	n.652-10C>G		intron_variant	Intron 4 of 5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.4470G>C	p.Glu1490Asp	missense_variant	Exon 32 of 40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Jul 12, 2011

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This mutation is denoted p.Glu1490Asp (E1490D) at the protein level and c.4470 G>C at the cDNA level. The Glu1490Asp variant in the MYH7 gene has not been reported previously as a disease-causing mutation or as a benign polymorphism, to our knowledge. Although Glu1490Asp results in a conservative amino acid substitution of one negatively charged, polar amino acid with another, it occurs at a position that is highly conserved throughout evolution. Additionally, in silico analysis predicts Glu1490Asp to be probably damaging to the protein structure/function. Mutations in nearby codons (Tyr1488Cys, Ser1491Cys, Glu1496Ala) have been reported in association with left ventricular non-compaction and HCM, further supporting the functional importance of this region of the protein. Glu1490Asp was not observed in up to 400 alleles from control individuals of African American and Caucasian ancestry tested at GeneDx, indicating it is not a common benign polymorphism in these populations. In summary, while the Glu1490Asp variant is a good candidate for a disease-causing mutation, we cannot unequivocally determine whether Glu1490Asp is a disease-causing mutation or a rare benign variant. The variant is found in HCM panel(s). -

not specified Uncertain:1

Feb 02, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Glu1490As p variant in MYH7 has not been previously reported in individuals with cardiomyo pathy and was absent from large population studies. Glutamic acid (Glu) at posit ion 1490 is highly conserved in mammals and across evolutionarily distant specie s and the change to aspartic acid (Asp) was predicted to be pathogenic using a c omputational tool clinically validated by our laboratory. This tool's pathogenic prediction is estimated to be correct 94% of the time (Jordan 2011). In summary , while there is some suspicion for a pathogenic role, the clinical significance of the p.Glu1490Asp variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
CardioboostCm	Pathogenic	0.94
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	0.61	D
MutationAssessor	Pathogenic	3.3	M
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-2.3	N
REVEL	Uncertain	0.63
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.059	T
Polyphen		1.0	D
Vest4		0.69
MutPred		0.53		Loss of methylation at K1485 (P = 0.2045);
MVP		0.96
MPC		1.5
ClinPred		0.95	D
GERP RS		4.3
Varity_R		0.58
gMVP		0.81

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: rs730880911; hg19: chr14-23886411;