rs148637119

chr17-10654947-C-Achr17-10654947-C-T

Variant summary

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

The NM_002470.4(MYH3):c.118G>T(p.Val40Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,890 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. V40M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MYH3 NM_002470.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.09

Genes affected

MYH3 (HGNC:7573): (myosin heavy chain 3) Myosin is a major contractile protein which converts chemical energy into mechanical energy through the hydrolysis of ATP. Myosin is a hexameric protein composed of a pair of myosin heavy chains (MYH) and two pairs of nonidentical light chains. This gene is a member of the MYH family and encodes a protein with an IQ domain and a myosin head-like domain. Mutations in this gene have been associated with two congenital contracture (arthrogryposis) syndromes, Freeman-Sheldon syndrome and Sheldon-Hall syndrome. [provided by RefSeq, Jul 2008]

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, MYH3

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH3	NM_002470.4	c.118G>T	p.Val40Leu	missense_variant	3/41	ENST00000583535.6
MYH3	XM_011523870.4	c.118G>T	p.Val40Leu	missense_variant	3/41
MYH3	XM_011523871.3	c.118G>T	p.Val40Leu	missense_variant	3/41
MYH3	XM_047436127.1	c.118G>T	p.Val40Leu	missense_variant	5/43

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH3	ENST00000583535.6	c.118G>T	p.Val40Leu	missense_variant	3/41	5	NM_002470.4	P1
MYH3	ENST00000582580.1	n.206G>T		non_coding_transcript_exon_variant	3/4	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461890 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727244

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: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

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

Invitae

Oct 22, 2023

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 40 of the MYH3 protein (p.Val40Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MYH3-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MYH3 protein function with a negative predictive value of 95%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.44	T
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.24	D
MetaRNN	Uncertain	0.62	D
MetaSVM	Uncertain	0.68	D
MutationAssessor	Uncertain	2.7	M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.74	T
Sift4G	Uncertain	0.0040	D
Polyphen		0.093	B
Vest4		0.47
MutPred		0.63		Loss of catalytic residue at V40 (P = 0.0578);
MVP		0.81
MPC		0.60
ClinPred		0.96	D
GERP RS		5.4
Varity_R		0.43
gMVP		0.44

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: rs148637119; hg19: chr17-10558264;