rs770597592

Positions:

• chr6-5613259-C-G
• chr6-5613259-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_006567.5(FARS2):​c.1156C>G​(p.Arg386Gly) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FARS2 NM_006567.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.20

Genes affected

FARS2 (HGNC:21062): (phenylalanyl-tRNA synthetase 2, mitochondrial) This gene encodes a protein that transfers phenylalanine to its cognate tRNA. This protein localizes to the mitochondrion and plays a role in mitochondrial protein translation. Mutations in this gene can cause combined oxidative phosphorylation deficiency 14 (Alpers encephalopathy). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96
• PP5: Variant 6-5613259-C-G is Pathogenic according to our data. Variant chr6-5613259-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 587673.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FARS2	NM_006567.5	c.1156C>G	p.Arg386Gly	missense_variant	6/7	ENST00000274680.9	NP_006558.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FARS2	ENST00000274680.9	c.1156C>G	p.Arg386Gly	missense_variant	6/7	1	NM_006567.5	ENSP00000274680.4
FARS2	ENST00000324331.10	c.1156C>G	p.Arg386Gly	missense_variant	6/7	1		ENSP00000316335.5
FARS2	ENST00000648580.1	n.1156C>G		non_coding_transcript_exon_variant	6/9			ENSP00000497889.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461060 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726858

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Combined oxidative phosphorylation defect type 14 Pathogenic:1 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jun 27, 2022	In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt FARS2 protein function. ClinVar contains an entry for this variant (Variation ID: 587673). This missense change has been observed in individual(s) with early infantile-encephalopathy with epilepsy (PMID: 27549011). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 386 of the FARS2 protein (p.Arg386Gly). -
Uncertain significance, criteria provided, single submitter	clinical testing	Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine	Jun 13, 2018	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.81
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.82	D;D
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	.;D
M_CAP	Pathogenic	0.39	D
MetaRNN	Pathogenic	0.96	D;D
MetaSVM	Uncertain	0.62	D
MutationAssessor	Pathogenic	3.5	M;M
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-6.1	D;D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.024	D;D
Sift4G	Uncertain	0.027	D;D
Polyphen		1.0	D;D
Vest4		0.98
MutPred		0.72		Gain of helix (P = 0.0861);Gain of helix (P = 0.0861);
MVP		0.97
MPC		0.75
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.91
gMVP		0.85

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs770597592; hg19: chr6-5613492;