rs146682969
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BS1_Supporting
The NM_053025.4(MYLK):c.4336G>A(p.Glu1446Lys) variant causes a missense change. The variant allele was found at a frequency of 0.000238 in 1,614,072 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E1446D) has been classified as Uncertain significance.
Frequency
Consequence
NM_053025.4 missense
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Likely_benign. The variant received -1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000118 AC: 18AN: 152188Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000111 AC: 28AN: 251468 AF XY: 0.000103 show subpopulations
GnomAD4 exome AF: 0.000250 AC: 366AN: 1461884Hom.: 0 Cov.: 32 AF XY: 0.000228 AC XY: 166AN XY: 727246 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000118 AC: 18AN: 152188Hom.: 0 Cov.: 32 AF XY: 0.000121 AC XY: 9AN XY: 74350 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Aortic aneurysm, familial thoracic 7 Uncertain:2Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
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Familial thoracic aortic aneurysm and aortic dissection Uncertain:2
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The p.E1446K variant (also known as c.4336G>A), located in coding exon 23 of the MYLK gene, results from a G to A substitution at nucleotide position 4336. The glutamic acid at codon 1446 is replaced by lysine, an amino acid with similar properties. In vitro studies demonstrated a partial reduction in enzyme activity, but functional impact has not been determined (Kwartler CS et al. Am. J. Hum. Genet., 2018 Jul;103:138-143). This amino acid position is well conserved in available vertebrate species. 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. -
not provided Uncertain:2
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Identified in association with aortic dissection in published literature (PMID: 29961567); Published functional studies suggest a damaging effect as the p.(E1446K) variant results in reduced enzyme activity compared to wildtype (PMID: 29961567); In silico analysis suggests that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 27463017, 29961567) -
not specified Uncertain:1
Variant summary: MYLK c.4336G>A (p.Glu1446Lys) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00011 in 251468 control chromosomes. The observed variant frequency is approximately 2 fold of the estimated maximal expected allele frequency for a pathogenic variant in MYLK causing Thoracic Aortic Aneurysms And Dissections phenotype (5e-05), strongly suggesting that the variant is benign. To our knowledge, no occurrence of c.4336G>A in individuals affected with Thoracic Aortic Aneurysms And Dissections has been reported. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in >50%-90% of normal activity (Kwartler_2018). Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at