rs770035560

Positions:

• chr6-5368823-C-G

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.253C>G​(p.Pro85Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: FARS2 NM_006567.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.57

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]

FARS2 (HGNC:):

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, 0.961
• PP5: Variant 6-5368823-C-G is Pathogenic according to our data. Variant chr6-5368823-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 587669.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.253C>G	p.Pro85Ala	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.253C>G	p.Pro85Ala	missense_variant	2/7	1	NM_006567.5	ENSP00000274680.4
FARS2	ENST00000324331.10	c.253C>G	p.Pro85Ala	missense_variant	2/7	1		ENSP00000316335.5
FARS2	ENST00000648580.1	n.253C>G		non_coding_transcript_exon_variant	2/9			ENSP00000497889.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251294 Hom.: 0 AF XY: 0.00000736 AC XY: 1 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: 0.00000342 AC: 5 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727244

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: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

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

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 14, 2021	This variant has been reported to affect FARS2 protein function (PMID: 27095821). 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. This variant has been observed in combination with another FARS2 variant in an individual affected with juvenile onset refractory epilepsy and progressive myoclonus (PMID: 27095821). ClinVar contains an entry for this variant (Variation ID: 587669). This variant is present in population databases (rs770035560, ExAC 0.002%). This sequence change replaces proline with alanine at codon 85 of the FARS2 protein (p.Pro85Ala). The proline residue is highly conserved and there is a small physicochemical difference between proline and alanine. -
Likely pathogenic, 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	0.82
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.64	D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	.;D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.96	D;D
MetaSVM	Uncertain	0.40	D
MutationAssessor	Pathogenic	4.2	H;H
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-7.4	D;D
REVEL	Pathogenic	0.69
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.88
MutPred		0.79		Gain of MoRF binding (P = 0.0365);Gain of MoRF binding (P = 0.0365);
MVP		0.94
MPC		0.66
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.92
gMVP		0.84

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: rs770035560; hg19: chr6-5369056;