rs776636237

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_053025.4(MYLK):​c.169C>T​(p.Arg57Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,612,208 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R57Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

MYLK
NM_053025.4 missense

Scores

3
12
4

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 3.41

Publications

4 publications found
Variant links:
Genes affected
MYLK (HGNC:7590): (myosin light chain kinase) This gene, a muscle member of the immunoglobulin gene superfamily, encodes myosin light chain kinase which is a calcium/calmodulin dependent enzyme. This kinase phosphorylates myosin regulatory light chains to facilitate myosin interaction with actin filaments to produce contractile activity. This gene encodes both smooth muscle and nonmuscle isoforms. In addition, using a separate promoter in an intron in the 3' region, it encodes telokin, a small protein identical in sequence to the C-terminus of myosin light chain kinase, that is independently expressed in smooth muscle and functions to stabilize unphosphorylated myosin filaments. A pseudogene is located on the p arm of chromosome 3. Four transcript variants that produce four isoforms of the calcium/calmodulin dependent enzyme have been identified as well as two transcripts that produce two isoforms of telokin. Additional variants have been identified but lack full length transcripts. [provided by RefSeq, Jul 2008]
MYLK Gene-Disease associations (from GenCC):
  • aortic aneurysm, familial thoracic 7
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • familial thoracic aortic aneurysm and aortic dissection
    Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen
  • megacystis-microcolon-intestinal hypoperistalsis syndrome 1
    Inheritance: AR Classification: STRONG Submitted by: G2P
  • connective tissue disorder
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
  • megacystis-microcolon-intestinal hypoperistalsis syndrome
    Inheritance: AD, AR Classification: SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.85

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYLKNM_053025.4 linkc.169C>T p.Arg57Trp missense_variant Exon 5 of 34 ENST00000360304.8 NP_444253.3 Q15746-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MYLKENST00000360304.8 linkc.169C>T p.Arg57Trp missense_variant Exon 5 of 34 5 NM_053025.4 ENSP00000353452.3 Q15746-1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152162
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000812
AC:
2
AN:
246382
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.0000635
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000904
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1460046
Hom.:
0
Cov.:
32
AF XY:
0.0000165
AC XY:
12
AN XY:
726258
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33424
American (AMR)
AF:
0.00
AC:
0
AN:
44572
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39648
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86064
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53156
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5246
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1111530
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60280
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.443
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152162
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41434
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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:
0.0000332
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Aortic aneurysm, familial thoracic 7 Uncertain:1
Jan 08, 2025
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 tryptophan, which is neutral and slightly polar, at codon 57 of the MYLK protein (p.Arg57Trp). This variant is present in population databases (rs776636237, gnomAD 0.008%). This variant has not been reported in the literature in individuals affected with MYLK-related conditions. ClinVar contains an entry for this variant (Variation ID: 539086). 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 MYLK protein function with a negative predictive value of 95%. 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. -

not specified Uncertain:1
Feb 20, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MYLK c.169C>T (p.Arg57Trp) results in a non-conservative amino acid change located in the Immunoglobulin subtype 2 (IPR003598) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8.1e-06 in 246382 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.169C>T in individuals affected with Thoracic Aortic Aneurysms And Dissections 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 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
Jul 15, 2019
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R57W variant (also known as c.169C>T), located in coding exon 2 of the MYLK gene, results from a C to T substitution at nucleotide position 169. The arginine at codon 57 is replaced by tryptophan, an amino acid with dissimilar properties, and is located in the Ig-like C2-type 1 domain. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Aortic aneurysm, familial thoracic 7;C5542316:Megacystis-microcolon-intestinal hypoperistalsis syndrome 1 Uncertain:1
Nov 11, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jul 26, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

MYLK-related disorder Uncertain:1
Feb 20, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The MYLK c.169C>T variant is predicted to result in the amino acid substitution p.Arg57Trp. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0082% of alleles in individuals of African descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.35
BayesDel_addAF
Uncertain
0.017
T
BayesDel_noAF
Uncertain
-0.030
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.60
.;.;.;D;.;D
Eigen
Uncertain
0.57
Eigen_PC
Uncertain
0.56
FATHMM_MKL
Benign
0.74
D
LIST_S2
Uncertain
0.95
.;D;D;D;.;.
M_CAP
Benign
0.067
D
MetaRNN
Pathogenic
0.85
D;D;D;D;D;D
MetaSVM
Benign
-0.50
T
MutationAssessor
Uncertain
2.3
M;M;M;M;M;M
PhyloP100
3.4
PrimateAI
Uncertain
0.65
T
PROVEAN
Uncertain
-3.0
D;.;D;D;D;D
REVEL
Uncertain
0.41
Sift
Uncertain
0.0010
D;.;D;D;D;D
Sift4G
Pathogenic
0.0
D;D;D;D;D;D
Polyphen
1.0
D;D;D;D;D;D
Vest4
0.81
MVP
0.83
MPC
0.59
ClinPred
0.94
D
GERP RS
3.5
Varity_R
0.14
gMVP
0.58
Mutation Taster
=91/9
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: rs776636237; hg19: chr3-123471382; COSMIC: COSV60614521; API