rs397517471

Positions:

• chr20-31826648-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 6P and 4B. PM2 PP3_Strong BS2

The NM_033118.4(MYLK2):​c.1016A>G​(p.His339Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MYLK2 NM_033118.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.15

Genes affected

MYLK2 (HGNC:16243): (myosin light chain kinase 2) This gene encodes a myosin light chain kinase, a calcium/calmodulin dependent enzyme, that is exclusively expressed in adult skeletal muscle. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985
• BS2: High AC in GnomAdExome4 at 5 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYLK2	NM_033118.4	c.1016A>G	p.His339Arg	missense_variant	7/13	ENST00000375985.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYLK2	ENST00000375985.5	c.1016A>G	p.His339Arg	missense_variant	7/13	1	NM_033118.4	P1
MYLK2	ENST00000375994.6	c.1016A>G	p.His339Arg	missense_variant	6/12	1		P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461894 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 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: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jul 12, 2021

The p.His339Arg variant in MYLK2 has not been previously reported in individuals with cardiomyopathy and was absent from large population studies. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. In summary, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM2_Supporting. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.61	D;D
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	.;D
M_CAP	Pathogenic	0.51	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Uncertain	0.37	D
MutationAssessor	Pathogenic	3.6	H;H
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-7.7	D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		0.52	P;P
Vest4		0.94
MutPred		0.90		Gain of MoRF binding (P = 0.2218);Gain of MoRF binding (P = 0.2218);
MVP		0.83
MPC		0.14
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.94
gMVP		0.85

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: rs397517471; hg19: chr20-30414451;