13-110705972-G-T

Variant names:

• chr13-110705972-G-T
• rs371950209
• NM_024537.4:c.122C>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_024537.4(CARS2):​c.122C>A​(p.Ala41Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000733 in 1,364,038 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 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. A41V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.3e-7 (0 hom.)
• Consequence: CARS2 NM_024537.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.31
• Publications: 0 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.098419905).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CARS2	NM_024537.4	c.122C>A	p.Ala41Asp	missense_variant	Exon 1 of 15	ENST00000257347.9	NP_078813.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CARS2	ENST00000257347.9	c.122C>A	p.Ala41Asp	missense_variant	Exon 1 of 15	1	NM_024537.4	ENSP00000257347.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.33e-7 AC: 1 AN: 1364038 Hom.: 0 Cov.: 31 AF XY: 0.00000149 AC XY: 1 AN XY: 673260

African (AFR) AF: 0.00 AC: 0 AN: 28612

American (AMR) AF: 0.00 AC: 0 AN: 32870

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24086

East Asian (EAS) AF: 0.00 AC: 0 AN: 33154

South Asian (SAS) AF: 0.00 AC: 0 AN: 76290

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 38680

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5508

European-Non Finnish (NFE) AF: 9.36e-7 AC: 1 AN: 1068208

Other (OTH) AF: 0.00 AC: 0 AN: 56630

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Combined oxidative phosphorylation defect type 27 Uncertain:1

Feb 22, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with CARS2-related conditions. This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 41 of the CARS2 protein (p.Ala41Asp). This variant is not present in population databases (gnomAD no frequency). 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: "Tolerated"; PolyPhen-2: "Possibly Damaging"; 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.093
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.48
CADD	Benign	15
DANN	Benign	0.90
DEOGEN2	Benign	0.084	T
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.017	N
LIST_S2	Benign	0.46	T
M_CAP	Benign	0.0096	T
MetaRNN	Benign	0.098	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.5	L
PhyloP100		-1.3
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-0.29	N
REVEL	Benign	0.13
Sift	Benign	0.49	T
Sift4G	Benign	0.60	T
Polyphen		0.0	B
Vest4		0.074
MutPred		0.43		Gain of relative solvent accessibility (P = 0.0215);
MVP		0.31
MPC		0.61
ClinPred		0.075	T
GERP RS		-0.26
PromoterAI		-0.11	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.16
gMVP		0.31
Mutation Taster		=95/5	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs371950209; hg19: chr13-111358319;