rs143389605
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP5
The NM_020320.5(RARS2):āc.442A>Gā(p.Thr148Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000574 in 1,613,050 control chromosomes in the GnomAD database, including 1 homozygotes. 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. T148S) has been classified as Uncertain significance.
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: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000388 AC: 59AN: 152228Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000548 AC: 137AN: 250070 AF XY: 0.000547 show subpopulations
GnomAD4 exome AF: 0.000594 AC: 867AN: 1460704Hom.: 1 Cov.: 30 AF XY: 0.000549 AC XY: 399AN XY: 726652 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000387 AC: 59AN: 152346Hom.: 0 Cov.: 32 AF XY: 0.000322 AC XY: 24AN XY: 74496 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:3Uncertain:5
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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: 31014978, 30634555, 33972171, 29977174, 35468344, 24123792, 40025839) -
PM3_Very Strong, PP3 -
This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 148 of the RARS2 protein (p.Thr148Ala). This variant is present in population databases (rs143389605, gnomAD 0.1%), and has an allele count higher than expected for a pathogenic variant. This missense change has been observed in individual(s) with clinical features of pontocerebellar hypoplasia (PMID: 24123792, 30634555). ClinVar contains an entry for this variant (Variation ID: 358237). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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. -
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Pontocerebellar hypoplasia type 6 Pathogenic:2Uncertain:2
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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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not specified Uncertain:1
Variant summary: RARS2 c.442A>G (p.Thr148Ala) results in a non-conservative amino acid change located in the Arginyl-tRNA synthetase, catalytic core domain 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 0.00055 in 250070 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in RARS2 causing Pontocerebellar Hypoplasia, Type 6 (0.00055 vs 0.0011), allowing no conclusion about variant significance. c.442A>G has been reported in the literature in an individual affected with psychomotor retardation, autism and ataxia and in another individual with delayed development, brain atrophy, pontecerebellar atropy (Neveling_2013, Roux_2021). Both patients are reported to be carrying a pathogenic second variant in RARS2. A third patient has been reported in the literature with a second allele of uncertain signfiicance who had ataxia (Jou_2019). These data indicate that the variant may 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: 33972171, 24123792, 34717047, 30634555). ClinVar contains an entry for this variant (Variation ID: 358237). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at