20-31821522-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_StrongBS2

The NM_033118.4(MYLK2):c.557C>T(p.Thr186Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000483 in 1,613,930 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T186K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000049 ( 0 hom. )

Consequence

MYLK2
NM_033118.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: -1.96

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: Benign. The variant received -8 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.03576237).

BS2

High AC in GnomAd4 at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYLK2	NM_033118.4 link	c.557C>T	p.Thr186Met	missense_variant	Exon 4 of 13	ENST00000375985.5	NP_149109.1	Q9H1R3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYLK2	ENST00000375985.5 link	c.557C>T	p.Thr186Met	missense_variant	Exon 4 of 13	1	NM_033118.4	ENSP00000365152.4		Q9H1R3
MYLK2	ENST00000375994.6 link	c.557C>T	p.Thr186Met	missense_variant	Exon 3 of 12	1		ENSP00000365162.2		Q9H1R3

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152250

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000392

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000996

AC:

AN:

251046

AF XY:

0.000103

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.000550

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000493

AC:

AN:

1461680

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

727136

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33470

American (AMR)

AF:

0.000492

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53228

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000396

AC:

AN:

1112010

Other (OTH)

AF:

0.0000331

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.505

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:

0.0000394

AC:

AN:

152250

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74374

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41456

American (AMR)

AF:

0.000392

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5204

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68056

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

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:

0.0000675

Hom.:

Bravo

AF:

0.0000718

ExAC

AF:

0.0000494

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:2Benign:1

Jun 05, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant classified as Uncertain Significance - Favor Benign. The Thr186Met varia nt in MYLK2 has not been reported in individuals with cardiomyopathy or in large population studies. Threonine (Thr) at position 186 is not well conserved in ev olution and several mammals (bushbaby, megabat and sloth) have a methionine (Met ) at this position, suggesting that this change may be tolerated. Additional com putational analyses (AlignGVGD, PolyPhen2, and SIFT) do not suggest a high likel ihood of impact to the protein. In summary, the lack of conservation and presenc e of this variant in other species suggests that this variant may be benign, but additional studies are needed to fully assess the clinical significance of this variant. -

Aug 10, 2020

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: MYLK2 c.557C>T (p.Thr186Met) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0001 in 251046 control chromosomes (gnomAD). The observed variant frequency is approximately 4-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 benign. To our knowledge, no occurrence of c.557C>T in individuals affected with Hypertrophic Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely benign. -

Nov 29, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.557C>T (p.T186M) alteration is located in exon 4 (coding exon 3) of the MYLK2 gene. This alteration results from a C to T substitution at nucleotide position 557, causing the threonine (T) at amino acid position 186 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Oct 06, 2022

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Has not been previously published as pathogenic or benign to our knowledge; In silico analysis supports that this missense variant does not alter protein structure/function -

Hypertrophic cardiomyopathy 1

Uncertain:1

Oct 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 186 of the MYLK2 protein (p.Thr186Met). This variant is present in population databases (rs727504591, gnomAD 0.06%), and has an allele count higher than expected for a pathogenic variant. 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: 178986). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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

0.067

BayesDel_addAF

Benign

-0.42

BayesDel_noAF

Benign

-0.49

CADD

Benign

0.25

(source)

DANN

Benign

0.92

DEOGEN2

Benign

0.24

T;T

Eigen

Benign

-1.0

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.010

LIST_S2

Benign

0.44

.;T

M_CAP

Benign

0.028

MetaRNN

Benign

0.036

T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

0.67

N;N

PhyloP100

-2.0

PrimateAI

Benign

0.22

PROVEAN

Benign

-0.47

N;N

REVEL

Benign

0.082

Sift

Uncertain

0.023

D;D

Sift4G

Benign

0.12

T;T

Polyphen

0.83

P;P

Vest4

0.075

MutPred

0.18

Loss of phosphorylation at T186 (P = 0.0017);Loss of phosphorylation at T186 (P = 0.0017);

MVP

0.47

MPC

0.090

ClinPred

0.046

GERP RS

-3.3

Varity_R

0.021

gMVP

0.20

Mutation Taster

=100/0

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