rs1555333437

Variant names:

• chr14-23387887-GC-CT
• rs1555333437
• NM_002471.4:c.4395_4396delGCinsAG

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3

The NM_002471.4(MYH6):​c.4395_4396delGCinsAG​(p.Gln1466Glu) variant causes a missense change involving the alteration of a conserved nucleotide. 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 MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. S1465S) has been classified as Benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: MYH6 NM_002471.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 9.59
• Publications: 0 publications found

Genes affected

MYH6 (HGNC:7576): (myosin heavy chain 6) Cardiac muscle myosin is a hexamer consisting of two heavy chain subunits, two light chain subunits, and two regulatory subunits. This gene encodes the alpha heavy chain subunit of cardiac myosin. The gene is located approximately 4kb downstream of the gene encoding the beta heavy chain subunit of cardiac myosin. Mutations in this gene cause familial hypertrophic cardiomyopathy and atrial septal defect 3. [provided by RefSeq, Feb 2017]

MYH6 Gene-Disease associations (from GenCC):

• hypertrophic cardiomyopathy 14

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Laboratory for Molecular Medicine
• Keppen-Lubinsky syndrome

  Inheritance: AD Classification: MODERATE Submitted by: Illumina
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• atrial septal defect 3

  Inheritance: AD Classification: LIMITED Submitted by: G2P
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH6	NM_002471.4	c.4395_4396delGCinsAG	p.Gln1466Glu	missense_variant		ENST00000405093.9	NP_002462.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH6	ENST00000405093.9	c.4395_4396delGCinsAG	p.Gln1466Glu	missense_variant		5	NM_002471.4	ENSP00000386041.3

Frequencies

GnomAD3 genomes Cov.: 31

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy 14 Uncertain:1

Jul 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine, which is neutral and polar, with glutamic acid, which is acidic and polar, at codon 1466 of the MYH6 protein (p.Gln1466Glu). Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This variant has not been reported in the literature in individuals affected with MYH6-related conditions. ClinVar contains an entry for this variant (Variation ID: 470540). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Dilated cardiomyopathy 1EE;C2750467:Hypertrophic cardiomyopathy 14;C3279790:Atrial septal defect 3;C3279791:Sick sinus syndrome 3, susceptibility to;C3495498:Hypertrophic cardiomyopathy 1 Uncertain:1

Sep 22, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype Uncertain:1

May 05, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.4395_4396delGCinsAG variant (also known as p.Q1466E), located in coding exon 29 of the MYH6 gene, results from an in-frame deletion of GC and insertion of AG at nucleotide positions 4395 to 4396. This results in the substitution of the glutamine residue for a glutamic acid residue at codon 1466, an amino acid with highly similar properties. Based on data from gnomAD, this allele has an overall frequency of 0.0008% (2/250274) total alleles studied. The highest observed frequency was 0.00006% (1/16190) of African/African American alleles. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be neutral by in silico analysis (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.6

Splicing

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

Other links and lift over

dbSNP: rs1555333437; hg19: chr14-23857096;