3-123737483-C-A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_053025.4(MYLK):​c.649G>T​(p.Val217Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V217V) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MYLK
NM_053025.4 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.57

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.2636143).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYLKNM_053025.4 linkc.649G>T p.Val217Phe missense_variant Exon 8 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.649G>T p.Val217Phe missense_variant Exon 8 of 34 5 NM_053025.4 ENSP00000353452.3 Q15746-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461878
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727234
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
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:
86246
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:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Aortic aneurysm, familial thoracic 7 Uncertain:1
Feb 17, 2024
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 phenylalanine, which is neutral and non-polar, at codon 217 of the MYLK protein (p.Val217Phe). This variant is not present in population databases (gnomAD no frequency). 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: 539072). 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 with a negative predictive value of 95%. 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
Dec 06, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.V217F variant (also known as c.649G>T), located in coding exon 5 of the MYLK gene, results from a G to T substitution at nucleotide position 649. The valine at codon 217 is replaced by phenylalanine, an amino acid with highly 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
Uncertain
0.40
BayesDel_addAF
Uncertain
0.027
T
BayesDel_noAF
Benign
-0.20
CADD
Benign
16
DANN
Benign
0.97
DEOGEN2
Benign
0.29
.;.;.;T;.;T
Eigen
Benign
-0.39
Eigen_PC
Benign
-0.22
FATHMM_MKL
Benign
0.58
D
LIST_S2
Benign
0.84
.;T;T;T;.;.
M_CAP
Benign
0.013
T
MetaRNN
Benign
0.26
T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.6
L;L;L;L;L;L
PhyloP100
1.6
PrimateAI
Benign
0.44
T
PROVEAN
Benign
-1.3
N;.;N;N;N;N
REVEL
Benign
0.27
Sift
Benign
0.60
T;.;T;T;T;T
Sift4G
Benign
0.34
T;T;T;T;T;T
Polyphen
0.040
B;B;B;B;B;B
Vest4
0.33
MutPred
0.59
Gain of sheet (P = 0.1451);Gain of sheet (P = 0.1451);Gain of sheet (P = 0.1451);Gain of sheet (P = 0.1451);Gain of sheet (P = 0.1451);Gain of sheet (P = 0.1451);
MVP
0.79
MPC
0.43
ClinPred
0.49
T
GERP RS
3.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.062
gMVP
0.58
Mutation Taster
=80/20
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs1553824777; hg19: chr3-123456330; API