NM_020320.5:c.1A>T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PVS1PS1_ModeratePM2PP5_Very_Strong

The NM_020320.5(RARS2):c.1A>T(p.Met1?) variant causes a initiator codon change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000347 in 1,614,092 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

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

RARS2
NM_020320.5 initiator_codon

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 1.90

Variant links:

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]

RARS2 links:

ORC3 (HGNC:8489): (origin recognition complex subunit 3) The origin recognition complex (ORC) is a highly conserved six subunits protein complex essential for the initiation of the DNA replication in eukaryotic cells. Studies in yeast demonstrated that ORC binds specifically to origins of replication and serves as a platform for the assembly of additional initiation factors such as Cdc6 and Mcm proteins. The protein encoded by this gene is a subunit of the ORC complex. Studies of a similar gene in Drosophila suggested a possible role of this protein in neuronal proliferation and olfactory memory. Alternatively spliced transcript variants encoding distinct isoforms have been reported for this gene. [provided by RefSeq, Jul 2008]

ORC3 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 20 ACMG points.

PVS1

Start lost variant, next in-frame start position is after 7 pathogenic variants. Next in-frame start position is after 176 codons. Genomic position: 87545625. Lost 0.303 part of the original CDS.

PS1

Another start lost variant in NM_020320.5 (RARS2) was described as [Pathogenic] in Lovd

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 6-87589957-T-A is Pathogenic according to our data. Variant chr6-87589957-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 974848.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RARS2	NM_020320.5 link	c.1A>T	p.Met1?	initiator_codon_variant	Exon 1 of 20	ENST00000369536.10	NP_064716.2	Q5T160
ORC3	NM_012381.4 link	c.-212T>A		upstream_gene_variant		ENST00000392844.8	NP_036513.2	Q9UBD5-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RARS2	ENST00000369536.10 link	c.1A>T	p.Met1?	initiator_codon_variant	Exon 1 of 20	1	NM_020320.5	ENSP00000358549.5		Q5T160
ORC3	ENST00000392844.8 link	c.-212T>A		upstream_gene_variant		1	NM_012381.4	ENSP00000376586.3		Q9UBD5-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152222

Hom.:

Cov.:

show subpopulations

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:

0.00000797

AC:

AN:

250932

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135824

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000376

AC:

AN:

1461870

Hom.:

Cov.:

AF XY:

0.0000330

AC XY:

AN XY:

727236

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000423

Gnomad4 OTH exome

AF:

0.0000993

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74376

show subpopulations

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:

0.0000282

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Jan 06, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Initiation codon variant in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 32860008, 26795593) -

Feb 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 12, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects the initiator methionine of the RARS2 mRNA. The next in-frame methionine is located at codon 176. This variant is present in population databases (rs774923951, gnomAD 0.003%). Disruption of the initiator codon has been observed in individual(s) with pontocerebellar hypoplasia (PMID: 26083569, 32860008). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 974848). This variant disrupts a region of the RARS2 protein in which other variant(s) (p.Ile9Val) have been observed in individuals with RARS2-related conditions (PMID: 22569581). 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. -

Dec 10, 2018

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

DNA sequence analysis of the RARS2 gene demonstrated a sequence change, c.1A>T, in the first exon which is predicted to affect the translation initiation codon p.Met1. This sequence change has been described in the gnomAD database with a low population frequency of 0.00081% (dbSNP rs774923951). This particular amino acid change does not appear to have been described in the literature in other patients with RARS2 related disorders, however, a different pathogenic sequence change affecting the same amino acid residue (p.Met1Val) has been described in the compound heterozygous state in two siblings with pontocerebellar hypoplasia type 6 (PCH6) with some additional symptoms such as cardiomyopathy, hydrops, and pulmonary hypoplasia (PMID: 26083569). -

Pontocerebellar hypoplasia type 6

Pathogenic:3

Centogene AG - the Rare Disease Company

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 19, 2021

MGZ Medical Genetics Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 03, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.37

BayesDel_noAF

Pathogenic

0.38

CADD

Benign

DANN

Benign

0.89

DEOGEN2

Benign

0.017

Eigen

Benign

-0.17

Eigen_PC

Benign

-0.092

FATHMM_MKL

Benign

0.48

LIST_S2

Uncertain

0.90

M_CAP

Pathogenic

0.38

MetaRNN

Pathogenic

0.98

MetaSVM

Benign

-0.84

PROVEAN

Benign

-0.69

REVEL

Uncertain

0.38

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

0.15

Vest4

0.84

MutPred

0.95

Loss of catalytic residue at M1 (P = 2e-04);

MVP

0.71

ClinPred

1.0

GERP RS

4.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.96

gMVP

0.63

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over