rs748825203

chr13-110647159-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_024537.4(CARS2):c.1135G>A(p.Ala379Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000343 in 1,459,352 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: CARS2 NM_024537.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.06

Genes affected

CARS2 (HGNC:25695): (cysteinyl-tRNA synthetase 2, mitochondrial) This gene encodes a putative member of the class I family of aminoacyl-tRNA synthetases. These enzymes play a critical role in protein biosynthesis by charging tRNAs with their cognate amino acids. This protein is encoded by the nuclear genome but is likely to be imported to the mitochondrion where it is thought to catalyze the ligation of cysteine to tRNA molecules. A splice-site mutation in this gene has been associated with a novel progressive myoclonic epilepsy disease with similar symptoms to MERRF syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.30196688).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CARS2	NM_024537.4	c.1135G>A	p.Ala379Thr	missense_variant	11/15	ENST00000257347.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CARS2	ENST00000257347.9	c.1135G>A	p.Ala379Thr	missense_variant	11/15	1	NM_024537.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000122 AC: 3 AN: 246168 Hom.: 0 AF XY: 0.00000749 AC XY: 1 AN XY: 133542

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000583

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000547

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000343 AC: 5 AN: 1459352 Hom.: 0 Cov.: 31 AF XY: 0.00000276 AC XY: 2 AN XY: 725854

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000673

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000151

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Combined oxidative phosphorylation defect type 27 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 05, 2019

This variant has not been reported in the literature in individuals with CARS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 521237). This variant is present in population databases (rs748825203, ExAC 0.03%). This sequence change replaces alanine with threonine at codon 379 of the CARS2 protein (p.Ala379Thr). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and threonine. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 08, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.43
Cadd	Benign	22
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.48	T
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.19
FATHMM_MKL	Benign	0.54	D
LIST_S2	Benign	0.84	T
M_CAP	Benign	0.039	D
MetaRNN	Benign	0.30	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.7	M
MutationTaster	Benign	1.0	D
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-2.0	N
REVEL	Benign	0.087
Sift	Benign	0.10	T
Sift4G	Benign	0.072	T
Polyphen		0.56	P
Vest4		0.34
MutPred		0.32		Gain of phosphorylation at A379 (P = 0.1168);
MVP		0.40
MPC		0.24
ClinPred		0.32	T
GERP RS		4.3
Varity_R		0.054
gMVP		0.35

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

Other links and lift over

dbSNP: rs748825203; hg19: chr13-111299506;