14-23394175-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_002471.4(MYH6):c.2578C>A(p.Arg860Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R860H) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MYH6 NM_002471.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.63

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, MYH6

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH6	NM_002471.4	c.2578C>A	p.Arg860Ser	missense_variant	21/39	ENST00000405093.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH6	ENST00000405093.9	c.2578C>A	p.Arg860Ser	missense_variant	21/39	5	NM_002471.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251484 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135920

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461892 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000374

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000251 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 30, 2017

The R860S variant in the MYH6 gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The R860S variant is not observed in large population cohorts (Lek et al., 2016). The R860S variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. This substitution occurs at a position that is conserved in mammals. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. We interpret R860S as a variant of uncertain significance -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.62
BayesDel_addAF	Uncertain	0.092	D
BayesDel_noAF	Benign	-0.11
Cadd	Benign	21
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.49	T;T
Eigen	Benign	-0.23
Eigen_PC	Benign	-0.12
FATHMM_MKL	Benign	0.32	N
LIST_S2	Uncertain	0.89	D;.
M_CAP	Benign	0.070	D
MetaRNN	Uncertain	0.61	D;D
MetaSVM	Uncertain	0.13	D
MutationAssessor	Benign	1.4	L;L
MutationTaster	Benign	0.99	D;D
PrimateAI	Benign	0.47	T
PROVEAN	Benign	-2.2	N;N
REVEL	Uncertain	0.45
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.049	D;D
Polyphen		0.11	B;B
Vest4		0.61
MutPred		0.52		Gain of phosphorylation at R860 (P = 0.0079);Gain of phosphorylation at R860 (P = 0.0079);
MVP		0.95
MPC		0.49
ClinPred		0.87	D
GERP RS		3.6
Varity_R		0.32
gMVP		0.80

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

Publications

LitVar

Other links and lift over

dbSNP: rs1025146248; hg19: chr14-23863384;