6-30915985-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP5
The NM_020442.6(VARS2):c.511C>T(p.Arg171Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,613,864 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. R171Q) has been classified as Uncertain significance.
Frequency
Consequence
NM_020442.6 missense
Scores
Clinical Significance
Conservation
Publications
- mitochondrial diseaseInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- combined oxidative phosphorylation defect type 20Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| VARS2 | NM_020442.6 | c.511C>T | p.Arg171Trp | missense_variant | Exon 6 of 30 | ENST00000676266.1 | NP_065175.4 | |
| VARS2 | NM_001167734.2 | c.601C>T | p.Arg201Trp | missense_variant | Exon 6 of 30 | NP_001161206.1 | ||
| VARS2 | NM_001167733.3 | c.91C>T | p.Arg31Trp | missense_variant | Exon 5 of 29 | NP_001161205.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000986 AC: 15AN: 152142Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000318 AC: 8AN: 251272 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000164 AC: 24AN: 1461722Hom.: 0 Cov.: 32 AF XY: 0.0000165 AC XY: 12AN XY: 727146 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000986 AC: 15AN: 152142Hom.: 0 Cov.: 32 AF XY: 0.0000942 AC XY: 7AN XY: 74324 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Combined oxidative phosphorylation defect type 20 Pathogenic:2
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Inborn genetic diseases Pathogenic:1
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not specified Uncertain:1
Variant summary: VARS2 c.511C>T (p.Arg171Trp) results in a non-conservative amino acid change in 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 2.4e-05 in 1606868 control chromosomes, predominantly at a frequency of 0.00039 within the African or African-American subpopulation in the gnomAD database (v4.1). This frequency is not significantly higher than estimated for a pathogenic variant in VARS2 causing Combined Oxidative Phosphorylation Defect Type 20, allowing no conclusion about variant significance. The variant, c.511C>T, has been observed in at least one compound heterozygous individual affected with Combined Oxidative Phosphorylation Defect Type 20 (Baertling_2017), who carried a pathogenic variant in trans. Authors of the study reported experimental evidence evaluating an impact on protein function, and demonstrated highly decreased VARS2 protein levels (residual protein level <30%) in patient derived fibroblasts (Baertling_2017). The following publication has been ascertained in the context of this evaluation (PMID: 27502409). ClinVar contains an entry for this variant (Variation ID: 488636). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
not provided Uncertain:1
VARS2: PM2, PM3 -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at