3-123700805-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP4

The NM_053025.4(MYLK):​c.2663G>A​(p.Arg888His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000929 in 1,614,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

MYLK
NM_053025.4 missense

Scores

2
7
10

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.08
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.2881117).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYLKNM_053025.4 linkc.2663G>A p.Arg888His missense_variant Exon 18 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.2663G>A p.Arg888His missense_variant Exon 18 of 34 5 NM_053025.4 ENSP00000353452.3 Q15746-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152206
Hom.:
0
Cov.:
31
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000318
AC:
8
AN:
251344
Hom.:
0
AF XY:
0.0000221
AC XY:
3
AN XY:
135878
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000202
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1461874
Hom.:
0
Cov.:
40
AF XY:
0.0000110
AC XY:
8
AN XY:
727242
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000134
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000719
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000656
AC:
1
AN:
152324
Hom.:
0
Cov.:
31
AF XY:
0.0000134
AC XY:
1
AN XY:
74480
show subpopulations
Gnomad4 AFR
AF:
0.00
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:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000434
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Aortic aneurysm, familial thoracic 7 Uncertain:1
Mar 04, 2022
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 histidine, which is basic and polar, at codon 888 of the MYLK protein (p.Arg888His). This variant is present in population databases (rs528507616, gnomAD 0.02%). 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: 423801). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MYLK 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
Jul 28, 2021
Genetics and Molecular Pathology, SA Pathology
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Uncertain:1
Jan 23, 2018
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The R888H variant has not been publishedas pathogenic or been reported as benign to our knowledge. It is not observed at a significant frequency in largepopulation cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The R888Hsubstitution occurs at a position where only amino acids with similar properties to arginine (R) are tolerated acrossspecies. However, R888H is a conservative amino acid substitution, which is not likely to impact secondary proteinstructure as these residues share similar properties. Finally, in silico analysis is inconsistent in its predictions as towhether or not the variant is damaging to the protein structure/function. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.23
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.19
CADD
Pathogenic
28
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.26
.;.;.;T;.;T
Eigen
Uncertain
0.47
Eigen_PC
Uncertain
0.49
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Benign
0.80
.;T;T;T;.;.
M_CAP
Benign
0.056
D
MetaRNN
Benign
0.29
T;T;T;T;T;T
MetaSVM
Uncertain
-0.23
T
MutationAssessor
Uncertain
2.2
M;.;M;M;.;M
PrimateAI
Uncertain
0.56
T
PROVEAN
Benign
-1.3
N;.;N;N;N;N
REVEL
Benign
0.18
Sift
Uncertain
0.0020
D;.;D;D;D;D
Sift4G
Pathogenic
0.0
D;D;D;D;D;D
Polyphen
0.96
D;D;D;D;D;D
Vest4
0.58
MutPred
0.38
Gain of sheet (P = 0.0266);.;Gain of sheet (P = 0.0266);Gain of sheet (P = 0.0266);.;Gain of sheet (P = 0.0266);
MVP
0.91
MPC
0.20
ClinPred
0.28
T
GERP RS
5.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.28
gMVP
0.21

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.

Other links and lift over

dbSNP: rs528507616; hg19: chr3-123419652; COSMIC: COSV100659219; COSMIC: COSV100659219; API