NM_020320.5:c.419T>G
Variant summary
Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1PP5_Very_Strong
The NM_020320.5(RARS2):c.419T>G(p.Phe140Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000397 in 1,613,180 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_020320.5 missense
Scores
Clinical Significance
Conservation
Publications
- mitochondrial diseaseInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- pontocerebellar hypoplasia type 6Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics, PanelApp Australia
- complex neurodevelopmental disorderInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
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ACMG classification
Our verdict: Pathogenic. The variant received 10 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152234Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000220 AC: 55AN: 250154 AF XY: 0.000177 show subpopulations
GnomAD4 exome AF: 0.0000411 AC: 60AN: 1460946Hom.: 0 Cov.: 30 AF XY: 0.0000358 AC XY: 26AN XY: 726764 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152234Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74378 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Pontocerebellar hypoplasia type 6 Pathogenic:5
The c.419T>G (p.Phe140Cys) variant affects a highly conserved amino acid and is predicted by multiple in silico tools to have a deleterious effect on protein function. This variant has been previously reported as a compound heterozygous change in individuals with pontocerebellar hypoplasia (PMID: 25356970, 26795593, 30921410, 31216405, 38438854). The c.419T>G (p.Phe140Cys) variant is present in the heterozygous state in the gnomAD v4 population database at a frequency of 0.004% (64/1613180), and is absent in the homozygous state, thus is presumed to be rare. Based on the available evidence, c.419T>G (p.Phe140Cys) is classified as Pathogenic. -
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Compound heterozygous pathogenic variants, c.1612delA (p.T538fs) and c.419T>G (p.F140C), in the RARS2 gene were detected in this individual. The c.1612delA change predicts a translation reading frameshift at amino acid 538 (p.T538fs) with subsequent premature translation termination and therefore is classified as pathogenic. The c.419T>G (p.F140C) variant has been previously reported as disease causing [PMID 26795593, 25356970]. Whole exome sequencing and Sanger sequencing also showed that the mother is heterozygous for c.1612delA (p.T538fs) and the father is heterozygous for c.419T>G (p.F140C). Whole exome sequencing and Sanger sequencing also showed the affected sibling is heterozygous for both changes in RARS2. Our data indicate that the two changes in the RARS2 gene are in trans configuration (compound heterozygous) in this patient and the affected sibling. -
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not provided Pathogenic:2
This sequence change replaces phenylalanine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 140 of the RARS2 protein (p.Phe140Cys). This variant is present in population databases (rs772887102, gnomAD 0.2%). This missense change has been observed in individual(s) with clinical features of pontocerebellar hypoplasia and/or pontocerebellar hypoplasia (PMID: 26795593). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 215055). 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 RARS2 protein function with a positive predictive value of 95%. 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: 25356970, 26795593, 30921410, 31216405, 34717047, 31160820, 37334785, 38438854) -
Inborn genetic diseases Pathogenic:1
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Pontoneocerebellar hypoplasia Pathogenic:1
Variant summary: RARS2 c.419T>G (p.Phe140Cys) results in a non-conservative amino acid change located in the Arginyl-tRNA synthetase, catalytic core domain (IPR035684) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00022 in 250154 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in RARS2 causing Pontocerebellar Hypoplasia, Type 6 (0.00022 vs 0.0011), allowing no conclusion about variant significance. c.419T>G has been reported in the literature as a compound heterozygous genotype in individuals with features of RARS1-related disorders such as Pontocerebellar Hypoplasia, Type 6 and early-infantile (<12 weeks) developmental and epileptic encephalopathy undergoing Diagnostic Exome Sequencing (WES) analysis (example, Farwell_2015, Heiberg_2016, Liu_2019, de Valles-Ibanez_2022). 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. Three 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 pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at