14-23427657-C-T

Variant names:

• chr14-23427657-C-T
• rs121913627
• NM_000257.4:c.1816G>A

Variant summary

Our verdict is Pathogenic. The variant received 21 ACMG points: 21P and 0B. PS3 PM1 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000257.4(MYH7):​c.1816G>A​(p.Val606Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,614,060 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 Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000280305: Cuda et al (1997) demonstrated that purified myosin from patients with p.Val606Met had decreased actin sliding velocities." and additional evidence is available in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V606L) has been classified as Likely pathogenic. The gene MYH7 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:31 O:1
• Conservation: PhyloP100: 2.54
• Publications: 75 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: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• MYH7-related skeletal myopathy

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
• 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

Specifications for MYH7 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 21 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV000280305: Cuda et al (1997) demonstrated that purified myosin from patients with p.Val606Met had decreased actin sliding velocities.; SCV002048322: Functional studies suggest the variant protein has altered kinetics compared to wildtype protein (Roopnarine 1998). A mouse model expressing the p.Val606Met variant exhibits largely normal cardiac function alone but develops mild HCM in response to cyclosporine and leads to a severe HCM phenotype in combination with another MYH7 variant (Blankenburg 2014).; SCV000696338: Functional studies (Blankenburg_Circulation Research_2014; Tripathi_Basic Res Cardiol_2011; Roopnarine_BJ_1998; and Cuda_JMRCM_1997) showed lower in vitro motility activity, decreased actin-activated ATPase activity, allelic imbalance, and a mouse model study showed that the variant causes very mild hypertrophic cardiomyopathy in mice, but the HCM phenotype becomes much more severe with the presence of another HCM mutation.; SCV000059401: Animal models in mice suggest that this variant can result in HCM (Blankenburg 2014 PMID: 24829265).; SCV000546283: Experimental studies have shown that this missense change affects MYH7 function (PMID: 9172070, 9826622, 18020371, 21769673, 24829265).; SCV001735188: Functional studies have shown the mutant protein to exhibit partially reduced ATPase activity (PMID: 9826622) and motility (PMID: 9172070).
• PM1: In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_000257.4
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr14-23427657-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 525016.
• 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 hypertrophic cardiomyopathy 1, Ebstein anomaly, left ventricular noncompaction, hypertrophic cardiomyopathy, dilated cardiomyopathy 1S, MYH7-related skeletal myopathy, congenital myopathy 7A, myosin storage, autosomal dominant, dilated cardiomyopathy, myopathy, myosin storage, autosomal recessive, arrhythmogenic right ventricular cardiomyopathy, myopathy, myosin storage, autosomal dominant, hyaline body myopathy, familial isolated dilated cardiomyopathy, congenital heart disease.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.947
• PP5: Variant 14-23427657-C-T is Pathogenic according to our data. Variant chr14-23427657-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 14091.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000257.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH7	NM_000257.4	MANE Select	c.1816G>A	p.Val606Met	missense	Exon 16 of 40	NP_000248.2	P12883
	MYH7	NM_001407004.1		c.1816G>A	p.Val606Met	missense	Exon 15 of 39	NP_001393933.1	P12883

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH7	ENST00000355349.4	TSL:1 MANE Select	c.1816G>A	p.Val606Met	missense	Exon 16 of 40	ENSP00000347507.3	P12883
	MYH7	ENST00000858540.1		c.1816G>A	p.Val606Met	missense	Exon 16 of 40	ENSP00000528599.1
	MYH7	ENST00000965955.1		c.1816G>A	p.Val606Met	missense	Exon 16 of 40	ENSP00000636014.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152174 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251476 AF XY: 0.00

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461886 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727240

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: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1112012

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152174 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74348

African (AFR) AF: 0.00 AC: 0 AN: 41434

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00000955 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
11	-	-	not provided (11)
5	-	-	Hypertrophic cardiomyopathy 1 (5)
3	-	-	Cardiovascular phenotype (3)
3	-	-	Hypertrophic cardiomyopathy (3)
2	-	-	Cardiomyopathy (2)
2	-	-	Myosin storage myopathy (2)
2	-	-	Primary familial hypertrophic cardiomyopathy (2)
1	-	-	Dilated cardiomyopathy 1S (1)
1	-	-	MYH7-related skeletal myopathy (1)
1	-	-	Myopathy, myosin storage, autosomal recessive (1)
-	-	-	MYH7-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.74
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	D
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.93	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Uncertain	0.76	D
MutationAssessor	Uncertain	2.7	M
PhyloP100		2.5
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-2.7	D
REVEL	Pathogenic	0.71
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		0.94	P
Vest4		0.59
MutPred		0.80		Gain of catalytic residue at L608 (P = 0.0146)
MVP		0.96
MPC		2.1
ClinPred		0.97	D
GERP RS		5.1
Varity_R		0.77
gMVP		0.63
Mutation Taster		=2/98	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

Other links and lift over

dbSNP: rs121913627; hg19: chr14-23896866; COSMIC: COSV62519806;