14-23400916-G-T

Variant names:

• chr14-23400916-G-T
• rs786205484
• NM_002471.4:c.1203C>A

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_002471.4(MYH6):​c.1203C>A​(p.Cys401*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH6 NM_002471.4 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 0.154
• Publications: 1 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: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 14-23400916-G-T is Pathogenic according to our data. Variant chr14-23400916-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 191043.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002471.4. 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
	MYH6	NM_002471.4	MANE Select	c.1203C>A	p.Cys401*	stop_gained	Exon 13 of 39	NP_002462.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH6	ENST00000405093.9	TSL:5 MANE Select	c.1203C>A	p.Cys401*	stop_gained	Exon 13 of 39	ENSP00000386041.3
	MYH6	ENST00000557461.2	TSL:5	n.1270C>A		non_coding_transcript_exon	Exon 13 of 14

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:1

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

Jun 21, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene or region of a gene for which loss of function is not a well-established mechanism of disease; Has not been previously published as pathogenic or benign to our knowledge

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Uncertain	0.29
Eigen_PC	Benign	0.10
FATHMM_MKL	Uncertain	0.84	D
PhyloP100		0.15
Vest4		0.90
GERP RS		2.1
Mutation Taster		=13/187	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: rs786205484; hg19: chr14-23870125;