3-123682239-C-T

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBS1_Supporting

The NM_053025.4(MYLK):c.3637G>A(p.Val1213Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000247 in 1,601,306 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign 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. V1213L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00026 ( 0 hom. )

Consequence

MYLK
NM_053025.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: 0.402

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.081061274).

BS1

Variant frequency is greater than expected in population nfe. gnomad4_exome allele frequency = 0.000264 (382/1449172) while in subpopulation NFE AF= 0.000306 (338/1106178). AF 95% confidence interval is 0.000279. There are 0 homozygotes in gnomad4_exome. There are 187 alleles in male gnomad4_exome subpopulation. Median coverage is 30. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYLK	NM_053025.4 link	c.3637G>A	p.Val1213Met	missense_variant	Exon 20 of 34	ENST00000360304.8	NP_444253.3	Q15746-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYLK	ENST00000360304.8 link	c.3637G>A	p.Val1213Met	missense_variant	Exon 20 of 34	5	NM_053025.4	ENSP00000353452.3		Q15746-1

Frequencies

GnomAD3 genomes

AF:

0.0000920

AC:

AN:

152134

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:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000176

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000104

AC:

AN:

229728

Hom.:

AF XY:

0.0000894

AC XY:

AN XY:

123110

show subpopulations

Gnomad AFR exome

AF:

0.000280

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000581

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000174

Gnomad OTH exome

AF:

0.000174

GnomAD4 exome

AF:

0.000264

AC:

382

AN:

1449172

Hom.:

Cov.:

AF XY:

0.000260

AC XY:

187

AN XY:

719220

show subpopulations

Gnomad4 AFR exome

AF:

0.000150

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000253

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000306

Gnomad4 OTH exome

AF:

0.000634

GnomAD4 genome

AF:

0.0000920

AC:

AN:

152134

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74312

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000176

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000108

Hom.:

Bravo

AF:

0.000106

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000660

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Aortic aneurysm, familial thoracic 7

Uncertain:2

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1213 of the MYLK protein (p.Val1213Met). This variant is present in population databases (rs368390254, gnomAD 0.02%). This missense change has been observed in individual(s) with thoracic aortic aneurysm or dissection (PMID: 21055718, 29543232). ClinVar contains an entry for this variant (Variation ID: 403212). 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 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. -

not specified

Uncertain:2

Apr 25, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: 1 proband, no segs in HGMD; ExAC: 5/27770 European chromosomes -

Feb 17, 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.3637G>A (p.Val1213Met) results in a conservative amino acid change in the encoded protein sequence. Four of four 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 230104 control chromosomes (gnomAD and publication data). The observed variant frequency is approximately 42 fold of the estimated maximal expected allele frequency for a pathogenic variant in MYLK causing Aortopathy phenotype (2.5e-06), strongly suggesting that the variant is benign. However, this observance needs to be cautiously considered due to the possibility of the MYLK pseudogene being captured. c.3637G>A has been reported in the literature in individuals affected with thoracic aortic aneurysm/aortic dissection (Wang_2010, Weerakkody_2018). These reports do not provide unequivocal conclusions about association of the variant with Aortopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight ClinVar submitters (evaluation after 2014) cite this variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -

not provided

Uncertain:2

Jul 09, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has been reported in association with TAAD, though no segregation data are described (PMID: 29543232, 21055718); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 29543232, 21055718, 21231930, 29544503) -

Feb 13, 2018

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The MYLK c.3637G>A; p.Val1213Met variant (rs368390254) has been reported in a single family with thoracic aortic aneurysms or aortic dissections (TAAD), but insufficient segregation data was available to determine whether or not the variant is associated with aortic disease (Wang 2010). This variant is listed in the genome Aggregation Database (gnomAD) with an overall population frequency of 0.009% (identified on 23 out of 255,410 chromosomes) and is classified as a variant of unknown significance in ClinVar (ID: 403212). The valine at position 1213 is weakly conserved, considering 12 species, and a methionine is found in this position in several species, suggesting this variant is evolutionarily tolerated. Computational analyses of the effects of the p.Val1213Met variant on protein structure and function do not predict a deleterious effect (SIFT: tolerated, PolyPhen-2: benign). Based on the available information, the clinical significance of the p.Val1213Met variant cannot be determined with certainty. -

Familial thoracic aortic aneurysm and aortic dissection

Uncertain:1

Jan 25, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.V1213M variant (also known as c.3637G>A), located in coding exon 17 of the MYLK gene, results from a G to A substitution at nucleotide position 3637. The valine at codon 1213 is replaced by methionine, an amino acid with highly similar properties, and is located in the actin-binding (calcium/calmodulin-sensitive) domain. This alteration was reported in association with familial thoracic aortic aneurysm and dissection (TAAD) (Wang L et al. Am. J. Hum. Genet., 2010 Nov;87:701-7; Weerakkody R et al. Genet Med, 2018 11;20:1414-1422). This amino acid position is well conserved in available vertebrate species; however, methionine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Atrial septal defect

Uncertain:1

Nov 11, 2015

Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Aortic aneurysm, familial thoracic 7;C5542316:Megacystis-microcolon-intestinal hypoperistalsis syndrome 1

Uncertain:1

Aug 27, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.34

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.34

CADD

Benign

DANN

Uncertain

0.98

DEOGEN2

Benign

0.20

.;.;.;T;.;T;T

Eigen

Benign

-0.55

Eigen_PC

Benign

-0.48

FATHMM_MKL

Benign

0.12

LIST_S2

Benign

0.84

.;T;T;T;.;.;T

M_CAP

Benign

0.016

MetaRNN

Benign

0.081

T;T;T;T;T;T;T

MetaSVM

Benign

-0.96

MutationAssessor

Benign

0.34

N;.;N;N;.;N;.

PrimateAI

Uncertain

0.50

PROVEAN

Benign

-0.47

N;.;N;N;N;N;N

REVEL

Benign

0.042

Sift

Benign

0.057

T;.;T;T;T;T;T

Sift4G

Pathogenic

0.0010

D;D;D;D;D;D;.

Polyphen

0.21

B;B;B;B;B;B;.

Vest4

0.28

MVP

0.70

MPC

0.37

ClinPred

0.046

GERP RS

2.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.030

gMVP

0.29

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over