17-10648592-C-A

Variant names:

• chr17-10648592-C-A
• rs121913623
• NM_002470.4:c.700G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_002470.4(MYH3):​c.700G>T​(p.Ala234Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,788 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. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A234T) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYH3 NM_002470.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.16
• Publications: 0 publications found

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]

MYHAS (HGNC:50609): (myosin heavy chain gene cluster antisense RNA) Predicted to enable primary miRNA binding activity. Predicted to be involved in response to muscle activity and skeletal muscle fiber development. Predicted to act upstream of or within with a positive effect on gene expression. Predicted to be located in cytoplasm and nucleus. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_002470.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-10648592-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 14145.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.972

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002470.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH3	NM_002470.4	MANE Select	c.700G>T	p.Ala234Ser	missense	Exon 8 of 41	NP_002461.2	P11055

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH3	ENST00000583535.6	TSL:5 MANE Select	c.700G>T	p.Ala234Ser	missense	Exon 8 of 41	ENSP00000464317.1	P11055
	MYH3	ENST00000961194.1		c.700G>T	p.Ala234Ser	missense	Exon 7 of 40	ENSP00000631253.1
	MYHAS	ENST00000579914.2	TSL:4	n.705+34715C>A		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461788 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727210

⚠️ 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: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111922

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	0.58
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.97	D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		6.2
PrimateAI	Pathogenic	0.81	D
Sift4G	Uncertain	0.059	T
Polyphen		0.47	P
Vest4		0.78
MutPred		0.89		Gain of disorder (P = 0.0452)
MVP		0.81
MPC		1.8
ClinPred		0.97	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.41
gMVP		0.67
Mutation Taster		=43/57	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs121913623; hg19: chr17-10551909;