chr14-23418385-C-G

Variant names:

• chr14-23418385-C-G
• rs397516198
• NM_000257.4:c.3994G>C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_000257.4(MYH7):​c.3994G>C​(p.Ala1332Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000206 in 1,459,412 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. A1332T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.82
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.908

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.3994G>C	p.Ala1332Pro	missense_variant	Exon 30 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.3994G>C	p.Ala1332Pro	missense_variant	Exon 29 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.3994G>C	p.Ala1332Pro	missense_variant	Exon 30 of 40	1	NM_000257.4	ENSP00000347507.3
MYH7	ENST00000713768.1	c.3994G>C	p.Ala1332Pro	missense_variant	Exon 30 of 41			ENSP00000519070.1
MYH7	ENST00000713769.1	c.3994G>C	p.Ala1332Pro	missense_variant	Exon 29 of 39			ENSP00000519071.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459412 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 725686

African (AFR) AF: 0.00 AC: 0 AN: 33432

American (AMR) AF: 0.00 AC: 0 AN: 44664

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26042

East Asian (EAS) AF: 0.00 AC: 0 AN: 39652

South Asian (SAS) AF: 0.00 AC: 0 AN: 86138

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52978

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5692

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1110546

Other (OTH) AF: 0.00 AC: 0 AN: 60268

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dilated cardiomyopathy 1S Uncertain:1

Feb 02, 2022

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3A. 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. Pathogenic variants in this gene are usually heterozygous, 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 alanine to proline. (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (8 heterozygotes, 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) 0708 - Another missense variant comparable to the one identified in this case has conflicting previous evidence for pathogenicity. An alternative change to a threonine has been reported multiple times as VUS in ClinVar, and in one DCM patient and two HCM patients in the literature (PMID: 21750094, 27532257). (I) 0807 - This variant has no previous evidence of pathogenicity. (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: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
CardioboostCm	Uncertain	0.89
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	D
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	0.66	D
MutationAssessor	Pathogenic	3.7	H
PhyloP100		4.8
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-3.4	D
REVEL	Pathogenic	0.66
Sift	Uncertain	0.0010	D
Sift4G	Benign	0.11	T
Polyphen		0.97	D
Vest4		0.78
MutPred		0.45		Gain of catalytic residue at Q1334 (P = 0.0064);
MVP		0.98
MPC		1.4
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.87
gMVP		0.95
Mutation Taster		=3/97	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs397516198; hg19: chr14-23887594;