22-50527612-C-T
Variant summary
Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2PP3PP5_Very_Strong
The NM_001953.5(TYMP):c.622G>A(p.Val208Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000441 in 1,613,832 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_001953.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 11 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000243 AC: 37AN: 152174Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.000326 AC: 82AN: 251306Hom.: 0 AF XY: 0.000339 AC XY: 46AN XY: 135874
GnomAD4 exome AF: 0.000462 AC: 675AN: 1461658Hom.: 0 Cov.: 35 AF XY: 0.000457 AC XY: 332AN XY: 727130
GnomAD4 genome AF: 0.000243 AC: 37AN: 152174Hom.: 0 Cov.: 33 AF XY: 0.000215 AC XY: 16AN XY: 74332
ClinVar
Submissions by phenotype
Mitochondrial DNA depletion syndrome 1 Pathogenic:8
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Variant summary: TYMP c.622G>A (p.Val208Met) results in a conservative amino acid change located in the Glycosyl transferase, family 3 domain (IPR000312) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00033 in 251306 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in TYMP causing Mitochondrial DNA Depletion Syndrome 1 (MNGIE type) (0.00033 vs 0.0011), allowing no conclusion about variant significance. c.622G>A has been reported in the literature in individuals affected with Mitochondrial DNA Depletion Syndrome 1 (MNGIE type; Marti_2005, Ronchi_2020, Levy_2021). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 16178026, 32849836, 33300680). ClinVar contains an entry for this variant (Variation ID: 16663). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
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not provided Pathogenic:4
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This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 208 of the TYMP protein (p.Val208Met). This variant is present in population databases (rs121913039, gnomAD 0.06%). This missense change has been observed in individual(s) with mitochondrial disease and/or mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) (PMID: 16178026, 32849836, 33300680). ClinVar contains an entry for this variant (Variation ID: 16663). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt TYMP protein function with a positive predictive value of 95%. Studies have shown that this missense change alters TYMP gene expression (PMID: 32849836). For these reasons, this variant has been classified as Pathogenic. -
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 16178026, 19853446, 19748572, 21412940, 30487145, 32384880, 34426522, 33300680, 32849836, 38712004) -
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at