NM_033118.4:c.1657C>T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BS2

The NM_033118.4(MYLK2):c.1657C>T(p.Arg553Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000305 in 1,608,884 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. R553R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

MYLK2
NM_033118.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.91

Publications

1 publications found

Variant links:

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]

MYLK2 Gene-Disease associations (from GenCC):

hypertrophic cardiomyopathy 1
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
hypertrophic cardiomyopathy
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

MYLK2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BS2

High AC in GnomAd4 at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYLK2	NM_033118.4 link	c.1657C>T	p.Arg553Cys	missense_variant	Exon 12 of 13	ENST00000375985.5	NP_149109.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
MYLK2	ENST00000375985.5 link	c.1657C>T	p.Arg553Cys	missense_variant	Exon 12 of 13	1	NM_033118.4	ENSP00000365152.4
MYLK2	ENST00000375994.6 link	c.1657C>T	p.Arg553Cys	missense_variant	Exon 11 of 12	1		ENSP00000365162.2
MYLK2	ENST00000468730.1 link	n.595C>T		non_coding_transcript_exon_variant	Exon 5 of 6	1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152128

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000334

AC:

AN:

239816

AF XY:

0.0000309

show subpopulations

Gnomad AFR exome

AF:

0.0000659

Gnomad AMR exome

AF:

0.0000300

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000554

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000288

AC:

AN:

1456638

Hom.:

Cov.:

AF XY:

0.0000207

AC XY:

AN XY:

724054

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33422

American (AMR)

AF:

0.0000685

AC:

AN:

43796

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25948

East Asian (EAS)

AF:

0.00

AC:

AN:

39564

South Asian (SAS)

AF:

0.0000470

AC:

AN:

85134

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53092

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.0000288

AC:

AN:

1109664

Other (OTH)

AF:

0.0000332

AC:

AN:

60258

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.456

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152246

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74430

show subpopulations

African (AFR)

AF:

0.0000481

AC:

AN:

41548

American (AMR)

AF:

0.00

AC:

AN:

15300

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.000193

AC:

AN:

5168

South Asian (SAS)

AF:

0.000207

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68012

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000169

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jun 07, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1657C>T (p.R553C) alteration is located in exon 12 (coding exon 11) of the MYLK2 gene. This alteration results from a C to T substitution at nucleotide position 1657, causing the arginine (R) at amino acid position 553 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Aug 22, 2016

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

p.Arg553Cys (CGC>TGC): c.1657 C>T in exon 12 of the MYLK2 gene (NM_033118.3). A variant of unknown significance has been identified in the MYLK2 gene. The R553C variant has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. The R553C variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The R553C variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. However, no missense mutations in nearby residues have been reported in association with cardiomyopathy, indicating this region of the protein may be tolerant of change. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic mutation or a rare benign variant. The variant is found in CARDIOMYOPATHY panel(s). -

Hypertrophic cardiomyopathy 1

Uncertain:1

Jun 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 553 of the MYLK2 protein (p.Arg553Cys). This variant is present in population databases (rs765059037, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with MYLK2-related conditions. ClinVar contains an entry for this variant (Variation ID: 201863). 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 MYLK2 protein function with a negative predictive value of 80%. 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

Benign

0.25

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.24

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.72

D;D

Eigen

Uncertain

0.45

Eigen_PC

Uncertain

0.48

FATHMM_MKL

Uncertain

0.93

LIST_S2

Benign

0.80

.;T

M_CAP

Benign

0.084

MetaRNN

Uncertain

0.49

T;T

MetaSVM

Benign

-0.43

MutationAssessor

Benign

1.7

L;L

PhyloP100

2.9

PrimateAI

Uncertain

0.74

PROVEAN

Pathogenic

-5.3

D;D

REVEL

Uncertain

0.38

Sift

Uncertain

0.0020

D;D

Sift4G

Pathogenic

0.0010

D;D

Polyphen

1.0

D;D

Vest4

0.45

MutPred

0.60

Gain of catalytic residue at L554 (P = 0.0152);Gain of catalytic residue at L554 (P = 0.0152);

MVP

0.79

MPC

0.42

ClinPred

0.45

GERP RS

4.9

Varity_R

0.30

gMVP

0.64

Mutation Taster

=94/6

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over