chr13-110706009-G-A

Variant names:

• chr13-110706009-G-A
• rs934745570
• NM_024537.4:c.85C>T

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.85C>T​(p.Pro29Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000375 in 1,333,100 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 (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000038 (0 hom.)
• Consequence: CARS2 NM_024537.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0730
• 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: 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=0.06717938).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CARS2	NM_024537.4	c.85C>T	p.Pro29Ser	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.85C>T	p.Pro29Ser	missense_variant	Exon 1 of 15	1	NM_024537.4	ENSP00000257347.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00 AC: 0 AN: 91464 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000375 AC: 5 AN: 1333100 Hom.: 0 Cov.: 31 AF XY: 0.00000304 AC XY: 2 AN XY: 657476

African (AFR) AF: 0.00 AC: 0 AN: 27080

American (AMR) AF: 0.00 AC: 0 AN: 28912

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 22522

East Asian (EAS) AF: 0.00 AC: 0 AN: 30956

South Asian (SAS) AF: 0.0000137 AC: 1 AN: 72864

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 34968

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5298

European-Non Finnish (NFE) AF: 0.00000284 AC: 3 AN: 1055228

Other (OTH) AF: 0.0000181 AC: 1 AN: 55272

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Combined oxidative phosphorylation defect type 27 Uncertain:1

May 24, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline with serine at codon 29 of the CARS2 protein (p.Pro29Ser). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and serine. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has not been reported in the literature in individuals with a CARS2-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.081
BayesDel_addAF	Benign	-0.28	T
BayesDel_noAF	Benign	-0.63
CADD	Benign	12
DANN	Benign	0.84
DEOGEN2	Benign	0.059	T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.038	N
LIST_S2	Benign	0.51	T
M_CAP	Benign	0.0070	T
MetaRNN	Benign	0.067	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.20	N
PhyloP100		-0.073
PrimateAI	Uncertain	0.69	T
PROVEAN	Benign	-0.55	N
REVEL	Benign	0.042
Sift	Benign	0.34	T
Sift4G	Benign	0.47	T
Polyphen		0.022	B
Vest4		0.23
MutPred		0.33		Gain of helix (P = 0.0225);
MVP		0.19
MPC		2.8
ClinPred		0.13	T
GERP RS		-0.37
PromoterAI		-0.086	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.033
gMVP		0.41
Mutation Taster		=98/2	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs934745570; hg19: chr13-111358356;