rs781417096

chr6-87514994-GT-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_020320.5(RARS2):c.1612del(p.Thr538HisfsTer4) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000558 in 1,613,402 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: RARS2 NM_020320.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 4.38

Genes affected

RARS2 (HGNC:21406): (arginyl-tRNA synthetase 2, mitochondrial) This nuclear gene encodes a protein that localizes to the mitochondria, where it catalyzes the transfer of L-arginine to its cognate tRNA, an important step in translation of mitochondrially-encoded proteins. Defects in this gene are a cause of pontocerebellar hypoplasia type 6 (PCH6). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.072 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-87514994-GT-G is Pathogenic according to our data. Variant chr6-87514994-GT-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 522857.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RARS2	NM_020320.5	c.1612del	p.Thr538HisfsTer4	frameshift_variant	19/20	ENST00000369536.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RARS2	ENST00000369536.10	c.1612del	p.Thr538HisfsTer4	frameshift_variant	19/20	1	NM_020320.5	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251372 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135844

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461212 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 726978

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74350

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pontocerebellar hypoplasia type 6 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	May 25, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Undiagnosed Diseases Network, NIH	Oct 07, 2016	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. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 31, 2023

This sequence change creates a premature translational stop signal (p.Thr538Hisfs*4) in the RARS2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 41 amino acid(s) of the RARS2 protein. This variant is present in population databases (rs781417096, gnomAD 0.004%). This variant has not been reported in the literature in individuals affected with RARS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 522857). This variant disrupts a region of the RARS2 protein in which other variant(s) (p.Arg560His) have been determined to be pathogenic (PMID: 31618753, 31665838, 35068129; Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs781417096; hg19: chr6-88224712;