13-110647162-G-C

Variant names:

• chr13-110647162-G-C
• rs79081036
• NM_024537.4:c.1132C>G

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.1132C>G​(p.Arg378Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,702 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R378H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CARS2 NM_024537.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.45
• 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=0.17981523).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CARS2	NM_024537.4	c.1132C>G	p.Arg378Gly	missense_variant	Exon 11 of 15	ENST00000257347.9	NP_078813.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CARS2	ENST00000257347.9	c.1132C>G	p.Arg378Gly	missense_variant	Exon 11 of 15	1	NM_024537.4	ENSP00000257347.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459702 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726014

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33452

American (AMR) AF: 0.00 AC: 0 AN: 44610

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 85908

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52352

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5742

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111524

Other (OTH) AF: 0.00 AC: 0 AN: 60316

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.40
CADD	Benign	19
DANN	Benign	0.94
DEOGEN2	Benign	0.16	T
Eigen	Benign	-0.53
Eigen_PC	Benign	-0.51
FATHMM_MKL	Benign	0.079	N
LIST_S2	Uncertain	0.87	D
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	2.0	M
PhyloP100		1.5
PrimateAI	Benign	0.40	T
PROVEAN	Uncertain	-2.4	N
REVEL	Benign	0.15
Sift	Benign	0.41	T
Sift4G	Benign	0.42	T
Polyphen		0.0010	B
Vest4		0.47
MutPred		0.56		Loss of methylation at R378 (P = 0.0353);
MVP		0.41
MPC		0.22
ClinPred		0.13	T
GERP RS		4.2
PromoterAI		0.047	Neutral
Varity_R		0.13
gMVP		0.30
Mutation Taster		=88/12	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: rs79081036; hg19: chr13-111299509;