chr3-123733770-C-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6

The NM_053025.4(MYLK):​c.1226G>A​(p.Arg409Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,892 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).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MYLK
NM_053025.4 missense

Scores

1
18

Clinical Significance

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

Conservation

PhyloP100: 2.36

Publications

2 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: Likely_benign. The variant received -3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.052912354).
BP6
Variant 3-123733770-C-T is Benign according to our data. Variant chr3-123733770-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 570241.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYLKNM_053025.4 linkc.1226G>A p.Arg409Lys 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
MYLKENST00000360304.8 linkc.1226G>A p.Arg409Lys missense_variant Exon 10 of 34 5 NM_053025.4 ENSP00000353452.3 Q15746-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000796
AC:
2
AN:
251162
AF XY:
0.00000737
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461892
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.600
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
32
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Aortic aneurysm, familial thoracic 7 Uncertain:1
Aug 24, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine with lysine at codon 409 of the MYLK protein (p.Arg409Lys). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and lysine. This variant is present in population databases (rs776506361, ExAC 0.009%). 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: "Benign"; Align-GVGD: "Class C0". The lysine 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 Benign:1
Dec 07, 2024
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.37
T
BayesDel_noAF
Benign
-0.59
CADD
Benign
12
DANN
Benign
0.81
DEOGEN2
Benign
0.17
.;.;.;T;.;T
Eigen
Benign
-1.1
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.18
N
LIST_S2
Benign
0.57
.;T;T;T;.;.
M_CAP
Benign
0.013
T
MetaRNN
Benign
0.053
T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.42
N;N;N;N;N;N
PhyloP100
2.4
PrimateAI
Benign
0.29
T
PROVEAN
Benign
-0.73
N;.;N;N;N;N
REVEL
Benign
0.071
Sift
Benign
0.54
T;.;T;T;T;T
Sift4G
Pathogenic
0.0
D;D;D;D;D;D
Polyphen
0.018
B;B;B;B;B;B
Vest4
0.085
MutPred
0.22
Gain of ubiquitination at R409 (P = 0.0082);Gain of ubiquitination at R409 (P = 0.0082);Gain of ubiquitination at R409 (P = 0.0082);Gain of ubiquitination at R409 (P = 0.0082);Gain of ubiquitination at R409 (P = 0.0082);Gain of ubiquitination at R409 (P = 0.0082);
MVP
0.54
MPC
0.16
ClinPred
0.030
T
GERP RS
3.6
Varity_R
0.10
gMVP
0.23
Mutation Taster
=82/18
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: rs776506361; hg19: chr3-123452617; COSMIC: COSV60614553; COSMIC: COSV60614553; API