14-23420200-G-GCCTCCAGCTCCT

Variant names:

• chr14-23420200-G-GCCTCCAGCTCCT
• rs1064792935
• NM_000257.4:c.3359_3370dupAGGAGCTGGAGG

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM4 PP5_Very_Strong

The NM_000257.4(MYH7):​c.3359_3370dupAGGAGCTGGAGG​(p.Glu1120_Glu1123dup) variant causes a conservative inframe insertion change. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type INS_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. A1124A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: MYH7 NM_000257.4 conservative_inframe_insertion
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 6.04
• Publications: 1 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: Pathogenic. The variant received 12 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 18 uncertain in NM_000257.4
• PM4: Nonframeshift variant in NON repetitive region in NM_000257.4.
• PP5: Variant 14-23420200-G-GCCTCCAGCTCCT is Pathogenic according to our data. Variant chr14-23420200-G-GCCTCCAGCTCCT is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 407195.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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH7	NM_000257.4	MANE Select	c.3359_3370dupAGGAGCTGGAGG	p.Glu1120_Glu1123dup	conservative_inframe_insertion	Exon 27 of 40	NP_000248.2
	MYH7	NM_001407004.1		c.3359_3370dupAGGAGCTGGAGG	p.Glu1120_Glu1123dup	conservative_inframe_insertion	Exon 26 of 39	NP_001393933.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH7	ENST00000355349.4	TSL:1 MANE Select	c.3359_3370dupAGGAGCTGGAGG	p.Glu1120_Glu1123dup	conservative_inframe_insertion	Exon 27 of 40	ENSP00000347507.3
	MYH7	ENST00000858540.1		c.3359_3370dupAGGAGCTGGAGG	p.Glu1120_Glu1123dup	conservative_inframe_insertion	Exon 27 of 40	ENSP00000528599.1
	MYH7	ENST00000965955.1		c.3359_3370dupAGGAGCTGGAGG	p.Glu1120_Glu1123dup	conservative_inframe_insertion	Exon 27 of 40	ENSP00000636014.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	Hypertrophic cardiomyopathy (1)
1	-	-	Inborn genetic diseases (1)
-	1	-	MYH7-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		6.0
Mutation Taster		=5/95	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs1064792935; hg19: chr14-23889409;