rs368410574

Variant names:

• chr13-110667370-C-T
• rs368410574
• NM_024537.4:c.889G>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_024537.4(CARS2):​c.889G>A​(p.Glu297Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,204 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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: 0.0000048 (0 hom.)
• Consequence: CARS2 NM_024537.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.187
• Publications: 1 publications found

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]

CARS2 Gene-Disease associations (from GenCC):

• combined oxidative phosphorylation defect type 27

  Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Laboratory for Molecular Medicine, G2P
• mitochondrial disease

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.05703926).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CARS2	NM_024537.4	c.889G>A	p.Glu297Lys	missense_variant	Exon 8 of 15	ENST00000257347.9	NP_078813.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CARS2	ENST00000257347.9	c.889G>A	p.Glu297Lys	missense_variant	Exon 8 of 15	1	NM_024537.4	ENSP00000257347.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461204 Hom.: 0 Cov.: 29 AF XY: 0.00000688 AC XY: 5 AN XY: 726912

African (AFR) AF: 0.0000299 AC: 1 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44648

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39670

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86122

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53396

Middle Eastern (MID) AF: 0.000173 AC: 1 AN: 5768

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111632

Other (OTH) AF: 0.00 AC: 0 AN: 60366

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Combined oxidative phosphorylation defect type 27 Uncertain:1

Apr 11, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 297 of the CARS2 protein (p.Glu297Lys). This variant is present in population databases (rs368410574, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with CARS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 475638). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The lysine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.065
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	8.1
DANN	Benign	0.50
DEOGEN2	Benign	0.13	T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.052	N
LIST_S2	Benign	0.82	T
M_CAP	Benign	0.0022	T
MetaRNN	Benign	0.057	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.28	N
PhyloP100		0.19
PrimateAI	Benign	0.22	T
PROVEAN	Benign	-1.1	N
REVEL	Benign	0.099
Sift	Benign	0.68	T
Sift4G	Benign	0.69	T
Polyphen		0.0070	B
Vest4		0.20
MVP		0.19
MPC		0.19
ClinPred		0.018	T
GERP RS		-9.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.041
gMVP		0.27
Mutation Taster		=93/7	polymorphism

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

Other links and lift over

dbSNP: rs368410574; hg19: chr13-111319717;