rs145555213

Positions:

• chr6-5368994-G-A
• chr6-5368994-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Moderate PP5_Moderate

The NM_006567.5(FARS2):​c.424G>A​(p.Asp142Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000752 in 1,461,888 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D142Y) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: FARS2 NM_006567.5 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.55

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 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-5368994-G-T is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.899
• PP5: Variant 6-5368994-G-A is Pathogenic according to our data. Variant chr6-5368994-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1521458.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FARS2	NM_006567.5	c.424G>A	p.Asp142Asn	missense_variant	2/7	ENST00000274680.9	NP_006558.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FARS2	ENST00000274680.9	c.424G>A	p.Asp142Asn	missense_variant	2/7	1	NM_006567.5	ENSP00000274680	P1
FARS2	ENST00000324331.10	c.424G>A	p.Asp142Asn	missense_variant	2/7	1		ENSP00000316335	P1
FARS2	ENST00000648580.1	c.424G>A	p.Asp142Asn	missense_variant, NMD_transcript_variant	2/9			ENSP00000497889

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251308 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135852

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.00000963 AC XY: 7 AN XY: 727248

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: 0.00000989

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Combined oxidative phosphorylation defect type 14 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 28, 2021

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. This variant disrupts the p.Asp142 amino acid residue in FARS2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26553276, 31665838). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. This variant has not been reported in the literature in individuals affected with FARS2-related conditions. This variant is present in population databases (rs145555213, ExAC 0.002%). This sequence change replaces aspartic acid with asparagine at codon 142 of the FARS2 protein (p.Asp142Asn). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and asparagine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.61	D;D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	.;D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.90	D;D
MetaSVM	Uncertain	0.62	D
MutationAssessor	Pathogenic	4.6	H;H
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-4.4	D;D
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;D
Vest4		0.84
MVP		0.94
MPC		0.64
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.85
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: rs145555213; hg19: chr6-5369227; COSMIC: COSV99213147; COSMIC: COSV99213147;