6-87524643-C-T

Variant names:

• chr6-87524643-C-T
• rs145189950
• NM_020320.5:c.888G>A

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6 BP7

The NM_020320.5(RARS2):​c.888G>A​(p.Thr296Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000108 in 1,610,332 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00011 (0 hom.)
• Consequence: RARS2 NM_020320.5 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:3
• Conservation: PhyloP100: -0.621

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 Likely_benign. Variant got -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.48).
• BP6: Variant 6-87524643-C-T is Benign according to our data. Variant chr6-87524643-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 289735.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=2}.
• BP7: Synonymous conserved (PhyloP=-0.621 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RARS2	NM_020320.5	c.888G>A	p.Thr296Thr	synonymous_variant	Exon 11 of 20	ENST00000369536.10	NP_064716.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RARS2	ENST00000369536.10	c.888G>A	p.Thr296Thr	synonymous_variant	Exon 11 of 20	1	NM_020320.5	ENSP00000358549.5

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152090 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000877 AC: 22 AN: 250892 Hom.: 0 AF XY: 0.000103 AC XY: 14 AN XY: 135646

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: 0.000425

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000704

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000115 AC: 167 AN: 1458242 Hom.: 0 Cov.: 30 AF XY: 0.000121 AC XY: 88 AN XY: 725674

Gnomad4 AFR exome AF: 0.0000898

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.000360

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000112

Gnomad4 OTH exome AF: 0.000116

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152090 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74288

Gnomad4 AFR AF: 0.0000724

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000491

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:2

Jan 15, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 21, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 24, 2020

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Pontocerebellar hypoplasia type 6 Uncertain:1 Benign:1

Sep 16, 2020

Natera, Inc.

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.48
CADD	Benign	1.6
DANN	Benign	0.63

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.16		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: rs145189950; hg19: chr6-88234361; COSMIC: COSV65759861;