17-10391910-T-A

Position:

• chr17-10391910-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_002472.3(MYH8):​c.5636A>T​(p.Lys1879Ile) variant causes a missense change involving the alteration of a 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH8 NM_002472.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.97

Genes affected

MYH8 (HGNC:7578): (myosin heavy chain 8) Myosins are actin-based motor proteins that function in the generation of mechanical force in eukaryotic cells. Muscle myosins are heterohexamers composed of 2 myosin heavy chains and 2 pairs of nonidentical myosin light chains. This gene encodes a member of the class II or conventional myosin heavy chains, and functions in skeletal muscle contraction. This gene is predominantly expressed in fetal skeletal muscle. This gene is found in a cluster of myosin heavy chain genes on chromosome 17. A mutation in this gene results in trismus-pseudocamptodactyly syndrome. [provided by RefSeq, Sep 2009]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYH8. . Gene score misZ 0.34953 (greater than the threshold 3.09). Trascript score misZ 3.2125 (greater than threshold 3.09). GenCC has associacion of gene with trismus-pseudocamptodactyly syndrome, Carney complex - trismus - pseudocamptodactyly syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.854

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH8	NM_002472.3	c.5636A>T	p.Lys1879Ile	missense_variant	39/40	ENST00000403437.2	NP_002463.2
MYHAS	NR_125367.1	n.76+8703T>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH8	ENST00000403437.2	c.5636A>T	p.Lys1879Ile	missense_variant	39/40	5	NM_002472.3	ENSP00000384330	P1
	ENST00000399342.6	n.76+8703T>A		intron_variant, non_coding_transcript_variant		3
	ENST00000581304.1	n.52+8703T>A		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 23, 2023

The c.5636A>T (p.K1879I) alteration is located in exon 39 (coding exon 37) of the MYH8 gene. This alteration results from a A to T substitution at nucleotide position 5636, causing the lysine (K) at amino acid position 1879 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.78
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.60	D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	4.4	H
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-4.9	D
REVEL	Pathogenic	0.85
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.69
MutPred		0.58		Loss of ubiquitination at K1879 (P = 0.0192);
MVP		0.95
MPC		1.1
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.71
gMVP		0.33

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: rs769925803; hg19: chr17-10295227;