NM_033118.4:c.557C>T

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

1
18

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

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
MYLK2NM_033118.4 linkc.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
MYLK2ENST00000375985.5 linkc.557C>T p.Thr186Met missense_variant Exon 4 of 13 1 NM_033118.4 ENSP00000365152.4 Q9H1R3
MYLK2ENST00000375994.6 linkc.557C>T p.Thr186Met missense_variant Exon 3 of 12 1 ENSP00000365162.2 Q9H1R3

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152250
Hom.:
0
Cov.:
33
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:
25
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:
72
AN:
1461680
Hom.:
0
Cov.:
32
AF XY:
0.0000523
AC XY:
38
AN XY:
727136
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.000492
AC:
22
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53228
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000396
AC:
44
AN:
1112010
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
Heterozygous variant carriers
0
5
10
15
20
25
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
6
AN:
152250
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74374
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.000392
AC:
6
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68056
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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.:
0
Bravo
AF:
0.0000718
ExAC
AF:
0.0000494
AC:
6
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
T
BayesDel_noAF
Benign
-0.49
CADD
Benign
0.25
DANN
Benign
0.92
DEOGEN2
Benign
0.24
T;T
Eigen
Benign
-1.0
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.010
N
LIST_S2
Benign
0.44
.;T
M_CAP
Benign
0.028
D
MetaRNN
Benign
0.036
T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.67
N;N
PhyloP100
-2.0
PrimateAI
Benign
0.22
T
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
T
GERP RS
-3.3
Varity_R
0.021
gMVP
0.20
Mutation Taster
=100/0
polymorphism

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

Other links and lift over

dbSNP: rs727504591; hg19: chr20-30409325; API