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FARS2 Mutations: More Than Two Phenotypes? A Case Report.

Mostafa Hotait¹, Wassim Nasreddine¹, Riyad El-Khoury²

¹Department of Neurology, American University of Beirut Medical Center, Beirut, Lebanon.

Frontiers in Genetics

|August 11, 2020

Summary

This summary is machine-generated.

Mutations in the FARS2 gene, encoding mitochondrial phenylalanyl-tRNA synthetase, can cause distinct neurological disorders. This study identifies a novel juvenile-onset refractory epilepsy phenotype linked to FARS2 gene variants.

Keywords:

FARS2 juvenile onset epilepsy mitochondrial epilepsy mitochondrial tRNA synthetase refractory status epilepticus

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Area of Science:

Genetics
Neuroscience
Mitochondrial Biology

Background:

The FARS2 gene encodes mitochondrial phenylalanyl-tRNA synthetase (mtPheRS).
FARS2 mutations have been previously associated with early-onset epileptic encephalopathy and spastic paraplegia.

Observation:

A 17-year-old female presented with severe, refractory focal motor status epilepticus, resistant to all medical interventions.
Emergency surgery was required to terminate the status epilepticus.
Muscle biopsy revealed mitochondrial proliferation and compensatory increases in specific mitochondrial enzyme activities (complexes II and IV).

Findings:

A novel hemizygous mutation in FARS2 (compound heterozygous state: p.V197M and exon 2 microdeletion) was identified as the cause.
The patient developed new focal aware motor seizures post-surgery, originating from a different brain hemisphere.
This case suggests a third distinct phenotypic manifestation of FARS2 gene mutations.

Implications:

This expands the known spectrum of FARS2-related disorders.
Highlights the complex genotype-phenotype correlations in mitochondrial diseases.
Emphasizes the need for considering FARS2 mutations in juvenile-onset refractory epilepsy.