rs768491774

chr13-110683060-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_024537.4(CARS2):c.646G>A(p.Gly216Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000562 in 1,600,408 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G216E) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: CARS2 NM_024537.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0510

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.14850771).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CARS2	NM_024537.4	c.646G>A	p.Gly216Arg	missense_variant	6/15	ENST00000257347.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CARS2	ENST00000257347.9	c.646G>A	p.Gly216Arg	missense_variant	6/15	1	NM_024537.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152202 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000167 AC: 4 AN: 239590 Hom.: 0 AF XY: 0.00000769 AC XY: 1 AN XY: 129968

Gnomad AFR exome AF: 0.0000651

Gnomad AMR exome AF: 0.0000318

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: 0.0000182

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000552 AC: 8 AN: 1448206 Hom.: 0 Cov.: 30 AF XY: 0.00000833 AC XY: 6 AN XY: 720362

Gnomad4 AFR exome AF: 0.0000308

Gnomad4 AMR exome AF: 0.0000236

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000260

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000361

Gnomad4 OTH exome AF: 0.0000167

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152202 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74354

Gnomad4 AFR AF: 0.0000241

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: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Combined oxidative phosphorylation defect type 27 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 20, 2018

This variant is present in population databases (rs768491774, ExAC 0.003%). 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. 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 tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with CARS2-related disease. This sequence change replaces glycine with arginine at codon 216 of the CARS2 protein (p.Gly216Arg). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.63
Cadd	Benign	15
Dann	Benign	0.81
DEOGEN2	Benign	0.24	T
Eigen	Benign	-0.70
Eigen_PC	Benign	-0.76
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.67	T
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.15	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.6	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-2.2	N
REVEL	Benign	0.11
Sift	Benign	0.26	T
Sift4G	Benign	0.13	T
Polyphen		0.31	B
Vest4		0.15
MutPred		0.56		Loss of catalytic residue at P212 (P = 0.1168);
MVP		0.40
MPC		0.26
ClinPred		0.068	T
GERP RS		2.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.057
gMVP		0.62

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs768491774; hg19: chr13-111335407; COSMIC: COSV99960088; COSMIC: COSV99960088;