rs3746597

Variant names:

• chr20-31821514-C-T
• rs3746597
• NM_033118.4:c.549C>T

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_Strong BP6_Very_Strong BP7 BS1 BS2

The NM_033118.4(MYLK2):​c.549C>T​(p.His183His) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00057 in 1,614,056 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00054 (1 hom., cov: 33)
  • Exomes 𝑓: 0.00057 (6 hom.)
• Consequence: MYLK2 NM_033118.4 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:8
• Conservation: PhyloP100: -2.35

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 Benign. Variant got -21 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.9).
• BP6: Variant 20-31821514-C-T is Benign according to our data. Variant chr20-31821514-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 46527.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-2.35 with no splicing effect.
• BS1: Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.000573 (838/1461680) while in subpopulation EAS AF= 0.0193 (765/39700). AF 95% confidence interval is 0.0181. There are 6 homozygotes in gnomad4_exome. There are 388 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High AC in GnomAd4 at 82 AD,Digenic gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYLK2	NM_033118.4	c.549C>T	p.His183His	synonymous_variant	Exon 4 of 13	ENST00000375985.5	NP_149109.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYLK2	ENST00000375985.5	c.549C>T	p.His183His	synonymous_variant	Exon 4 of 13	1	NM_033118.4	ENSP00000365152.4
MYLK2	ENST00000375994.6	c.549C>T	p.His183His	synonymous_variant	Exon 3 of 12	1		ENSP00000365162.2

Frequencies

GnomAD3 genomes AF: 0.000532 AC: 81 AN: 152258 Hom.: 1 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.0138

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.000282

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00131 AC: 329 AN: 251068 Hom.: 4 AF XY: 0.00123 AC XY: 167 AN XY: 135810

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0168

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.000647

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.000490

GnomAD4 exome AF: 0.000573 AC: 838 AN: 1461680 Hom.: 6 Cov.: 32 AF XY: 0.000534 AC XY: 388 AN XY: 727138

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0193

Gnomad4 SAS exome AF: 0.000104

Gnomad4 FIN exome AF: 0.000432

Gnomad4 NFE exome AF: 0.0000117

Gnomad4 OTH exome AF: 0.000447

GnomAD4 genome AF: 0.000538 AC: 82 AN: 152376 Hom.: 1 Cov.: 33 AF XY: 0.000684 AC XY: 51 AN XY: 74512

Gnomad4 AFR AF: 0.0000240

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.0141

Gnomad4 SAS AF: 0.000414

Gnomad4 FIN AF: 0.000282

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000121 Hom.: 0

Bravo AF: 0.000672

Asia WGS AF: 0.00231 AC: 8 AN: 3478

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:4

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	May 24, 2022	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Feb 05, 2018	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jun 01, 2012	2.5% (18/734) Asian alleles from JBIC-allele - East Asian population in dbSNP -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 17, 2023	Variant summary: MYLK2 c.549C>T results in a synonymous change. The variant allele was found at a frequency of 0.0013 in 251068 control chromosomes, predominantly at a frequency of 0.017 within the East Asian subpopulation in the gnomAD database, including 4 homozygotes. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 700 fold of the estimated maximal expected allele frequency for a pathogenic variant in MYLK2 causing Hypertrophic Cardiomyopathy phenotype (2.5e-05), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. To our knowledge, no occurrence of c.549C>T in individuals affected with Hypertrophic Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign. -

MYLK2-related disorder Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 19, 2024

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Cardiomyopathy Benign:1

Benign, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Jan 19, 2016

- -

not provided Benign:1

Benign, criteria provided, single submitter

not provided

Breakthrough Genomics, Breakthrough Genomics

-

- -

Hypertrophic cardiomyopathy 1 Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 01, 2025

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.90
CADD	Benign	0.16
DANN	Benign	0.41

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: rs3746597; hg19: chr20-30409317;