14-23389062-AG-GC

Position:

• chr14-23389062-AG-GC

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP6

The NM_002471.4(MYH6):​c.3979-8_3979-7delinsGC variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 0)
• Consequence: MYH6 NM_002471.4 splice_region, splice_polypyrimidine_tract, intron
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:5
• Conservation: PhyloP100: 0.275

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]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• BP6: Variant 14-23389062-AG-GC is Benign according to our data. Variant chr14-23389062-AG-GC is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 164227.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Benign=2, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH6	NM_002471.4	c.3979-8_3979-7delinsGC		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000405093.9	NP_002462.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH6	ENST00000405093.9	c.3979-8_3979-7delinsGC		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		5	NM_002471.4	ENSP00000386041	P1

Frequencies

GnomAD3 genomes Cov.: 0

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

GnomAD4 genome Cov.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1 Benign:3

Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jun 19, 2014	Variant classified as Uncertain Significance - Favor Benign. The 3979-8_3979-7de linsGC in MYH6 has been identified by our laboratory in 2 adults with DCM +/- co nduction system disease. Data from large populations studies is insufficient to assess the frequency of this variant. This region of intron 28 includes a homopo lymer region with a string of C divided by a single T and is highly variable wit h multiple variations on this sequence having been identified. Due the variabili ty that has been seen in this region and because the MYH6 gene has not yet been strongly associated with cardiomyopathy, this variant is less likely to contribu te to disease. In summary, though its clinical significance is uncertain, the va riation in this region suggests that it is more likely to be benign. -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 15, 2021	Variant summary: MYH6 c.3979-8_3979-7delinsGC alters a nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. This variant is reported as two separate variants in gnomAD, specifically c.3979-8C>G with an allele frequency of 0.001990 in 181896 control chromosomes (including 3 homozygotes) and c.3979-7T>C with an allele frequency of 0.05366 in 162742 control chromosomes (also including 3 homozygotes). Read data in gnomAD show the two variants in cis in multiple individuals (heterozygous and homozygous). Both frequencies significantly exceed the estimated maximal expected allele frequency for a pathogenic variant in MYH6 causing Cardiomyopathy phenotype (2.5e-05), strongly suggesting that the variant is a benign polymorphism. To our knowledge, no occurrence of c.3979-8_3979-7delinsGC in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. A co-occurrence with a pathogenic variant has been reported (MYBPC3 c.2827C>T, p.Arg943X; Internal testing), providing further supporting evidence for a benign role. One ClinVar submitter (evaluation after 2014) cites the variant as uncertain significance while another ClinVar submitter (evaluation after 2014) cites it as likely benign. Based on the evidence outlined above, the variant was classified as benign. -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Nov 26, 2015

- -

Hypertrophic cardiomyopathy 14 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 08, 2023

- -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Nov 17, 2016

- -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs727503235; hg19: chr14-23858271;