3-123722130-T-C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_053025.4(MYLK):​c.1802A>G​(p.His601Arg) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000958 in 1,565,272 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 19/24 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. H601P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.0000092 ( 0 hom. )

Consequence

MYLK
NM_053025.4 missense, splice_region

Scores

19
Splicing: ADA: 0.0006896
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.750

Publications

3 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 -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.091726035).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYLKNM_053025.4 linkc.1802A>G p.His601Arg missense_variant, splice_region_variant Exon 13 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.1802A>G p.His601Arg missense_variant, splice_region_variant Exon 13 of 34 5 NM_053025.4 ENSP00000353452.3 Q15746-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152252
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000115
AC:
2
AN:
173830
AF XY:
0.0000108
show subpopulations
Gnomad AFR exome
AF:
0.00
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:
0.0000141
Gnomad OTH exome
AF:
0.000214
GnomAD4 exome
AF:
0.00000920
AC:
13
AN:
1413020
Hom.:
0
Cov.:
42
AF XY:
0.00000573
AC XY:
4
AN XY:
698348
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32258
American (AMR)
AF:
0.00
AC:
0
AN:
37872
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25280
East Asian (EAS)
AF:
0.000108
AC:
4
AN:
36906
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79970
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49576
Middle Eastern (MID)
AF:
0.000350
AC:
2
AN:
5718
European-Non Finnish (NFE)
AF:
0.00000644
AC:
7
AN:
1086858
Other (OTH)
AF:
0.00
AC:
0
AN:
58582
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000131
AC:
2
AN:
152252
Hom.:
0
Cov.:
34
AF XY:
0.0000134
AC XY:
1
AN XY:
74380
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41472
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10632
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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

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:
0.0000772
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Aortic aneurysm, familial thoracic 7 Uncertain:1
Aug 20, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 601 of the MYLK protein (p.His601Arg). This variant is present in population databases (rs45477891, gnomAD 0.004%). 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: 862687). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The arginine 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.24
BayesDel_addAF
Benign
-0.27
T
BayesDel_noAF
Benign
-0.55
CADD
Benign
5.0
DANN
Benign
0.19
DEOGEN2
Benign
0.21
.;.;.;T;.;T
Eigen
Benign
-1.3
Eigen_PC
Benign
-1.3
FATHMM_MKL
Benign
0.15
N
LIST_S2
Benign
0.59
.;T;T;T;.;.
M_CAP
Benign
0.021
T
MetaRNN
Benign
0.092
T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.15
N;.;N;N;.;N
PhyloP100
0.75
PrimateAI
Benign
0.23
T
PROVEAN
Benign
-0.36
N;.;N;N;N;N
REVEL
Benign
0.078
Sift
Benign
0.31
T;.;T;T;T;T
Sift4G
Benign
0.31
T;T;T;T;T;T
Polyphen
0.0010
B;B;B;B;B;B
Vest4
0.15
MVP
0.46
MPC
0.19
ClinPred
0.035
T
GERP RS
-0.84
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.12
gMVP
0.40
Mutation Taster
=81/19
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00069
dbscSNV1_RF
Benign
0.068
SpliceAI score (max)
0.13
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: rs45477891; hg19: chr3-123440977; API