chr3-123733873-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_053025.4(MYLK):c.1123G>A(p.Ala375Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,794 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

MYLK
NM_053025.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: -0.164

Publications

0 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

MYLK links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

BP4

Computational evidence support a benign effect (MetaRNN=0.050584495).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYLK	NM_053025.4 link	c.1123G>A	p.Ala375Thr	missense_variant	Exon 10 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.1123G>A	p.Ala375Thr	missense_variant	Exon 10 of 34	5	NM_053025.4	ENSP00000353452.3		Q15746-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461794

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727162

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000756

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86160

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1112010

Other (OTH)

AF:

0.000149

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.471

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

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.00000824

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

May 16, 2023

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; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function -

Sep 02, 2022

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aortic aneurysm, familial thoracic 7

Uncertain:1

Aug 31, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine with threonine at codon 375 of the MYLK protein (p.Ala375Thr). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and threonine. This variant is present in population databases (rs374894375, ExAC 0.01%). This variant has not been reported in the literature in individuals affected with MYLK-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Familial thoracic aortic aneurysm and aortic dissection

Uncertain:1

Nov 17, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A375T variant (also known as c.1123G>A), located in coding exon 7 of the MYLK gene, results from a G to A substitution at nucleotide position 1123. The alanine at codon 375 is replaced by threonine, an amino acid with similar properties. This amino acid position is conserved. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.53

CADD

Benign

2.2

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.16

.;.;.;T;.;T

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.031

LIST_S2

Benign

0.66

.;T;T;T;.;.

M_CAP

Benign

0.032

MetaRNN

Benign

0.051

T;T;T;T;T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.1

L;L;L;L;L;L

PhyloP100

-0.16

PrimateAI

Benign

0.26

PROVEAN

Benign

-0.68

N;.;N;N;N;N

REVEL

Benign

0.10

Sift

Benign

0.17

T;.;T;T;T;T

Sift4G

Benign

0.061

T;T;T;T;T;T

Polyphen

0.0080

B;B;B;B;B;B

Vest4

0.076

MutPred

0.23

Gain of phosphorylation at A375 (P = 2e-04);Gain of phosphorylation at A375 (P = 2e-04);Gain of phosphorylation at A375 (P = 2e-04);Gain of phosphorylation at A375 (P = 2e-04);Gain of phosphorylation at A375 (P = 2e-04);Gain of phosphorylation at A375 (P = 2e-04);

MVP

0.45

MPC

0.48

ClinPred

0.097

GERP RS

-2.8

Varity_R

0.028

gMVP

0.21

Mutation Taster

=97/3

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over