title: Mutations in FARS2 and non-fatal mitochondrial dysfunction in two siblings.
abstract: Recently, mutations in FARS2, which encodes for mitochondrial phenylalanyl-tRNA synthetase, have been implicated in autosomal recessive combined oxidative phosphorylation deficiency 14. Associated clinical features in three previously reported patients with confirmed FARS2 mutations include infantile onset epilepsy, and a fatal Alpers-like encephalopathy. Herein, we report on two siblings with global developmental delay, dysarthria and tremor and compound heterozygous FARS2 abnormalities. They have a heterozygous missense mutation, c.1255C>T which predicts p.Arg419Cys in exon 7 of FARS2, inherited from their father and uncovered on exome sequencing, and an interstitial deletion of chromosome 6p25.1 inherited from their mother and uncovered on SNP array. This interstitial deletion includes all of exon 6 and parts of introns 5 and 6 of FARS2. Biochemical studies were also consistent with a mitochondrial disorder. While these siblings had considerable developmental difficulties, they are making consistent developmental progress and appear to be considerably less severely affected than the other patients reported in the literature with FARS2 associated mitochondrial disease. Thus, this study expands the phenotypic spectrum of FARS2 related disease and emphasizes intragenic deletion in the list of causative mutations.
authors: Department of Neurogenetics, Hugo W. Moser Research Institute at Kennedy Krieger Institute, Baltimore, Maryland; McKusick-Nathans Institute of Genetic Medicine, Baltimore, Maryland; Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors: Hilary J
authors: HJ
authors: Vernon
authors: Rebecca
authors: R
authors: McClellan
authors: Denise A S
authors: DA
authors: Batista
authors: Sakkubai
authors: S
authors: Naidu
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D059472:Exome / Q000235:genetics; D005091:Exons / Q000235:genetics; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008928:Mitochondria / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D028361:Mitochondrial Diseases / Q000000981:diagnostic imaging / Q000235:genetics* / Q000503:physiopathology; D020125:Mutation, Missense; D010375:Pedigree; D010652:Phenylalanine-tRNA Ligase / Q000235:genetics*; D011859:Radiography; D035781:Siblings; D066127:White Matter / Q000000981:diagnostic imaging / Q000503:physiopathology
chemical_list: D010652:Phenylalanine-tRNA Ligase
keywords: FARS2; exome sequencing; mitochondrial tRNA synthetase