NM_002471.4:c.1449C>A

Variant names:

• chr14-23400388-G-T
• rs145447555
• NM_002471.4:c.1449C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_002471.4(MYH6):​c.1449C>A​(p.Asn483Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,872 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. N483N) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYH6 NM_002471.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.31
• Publications: 2 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.962

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.1449C>A	p.Asn483Lys	missense	Exon 14 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.1449C>A	p.Asn483Lys	missense	Exon 14 of 39	ENSP00000386041.3
	MYH6	ENST00000557461.2	TSL:5	n.1516C>A		non_coding_transcript_exon	Exon 14 of 14

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251456 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: 6.84e-7 AC: 1 AN: 1461872 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727240

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44720

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: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60390

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Uncertain	0.089	D
BayesDel_noAF	Benign	-0.11
CADD	Benign	6.2
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D
Eigen	Benign	-0.13
Eigen_PC	Benign	-0.43
FATHMM_MKL	Benign	0.17	N
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Pathogenic	3.9	H
PhyloP100		-2.3
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-4.9	D
REVEL	Pathogenic	0.70
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.010	D
Polyphen		0.94	P
Vest4		0.97
MutPred		0.83		Gain of catalytic residue at I479 (P = 0.0067)
MVP		0.93
MPC		1.2
ClinPred		0.99	D
GERP RS		-5.0
Varity_R		0.84
gMVP		1.0
Mutation Taster		=30/70	disease causing

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: rs145447555; hg19: chr14-23869597;