Yusuke Takezawa1, Hiromi Fujie2, Atsuo Kikuchi3, Tetsuya Niihori4, Ryo Funayama5, Matsuyuki Shirota6, Keiko Nakayama5, Yoko Aoki4, Masayuki Sasaki7, Shigeo Kure1. 1. Department of Pediatrics, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan. 2. Department of Pediatrics, Iwaki Kyoritsu General Hospital, 16 Kuzehara, Mimayamachi, Uchigo, Iwaki, Fukushima 973-8555, Japan. 3. Department of Pediatrics, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan. Electronic address: akikuchi-thk@umin.ac.jp. 4. Department of Medical Genetics, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan. 5. Division of Cell Proliferation, United Centers for Advanced Research and Translational Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. 6. Division of Interdisciplinary Medical Sciences, United Centers for Advanced Research and Translational Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. 7. Department of Child Neurology, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi-cho, Kodaira, Tokyo 187-8551, Japan.
Abstract
BACKGROUND: IARS2 encodes isoleucine-tRNA synthetase, which is aclass-1 amino acyl-tRNA synthetase. IARS2 mutations are reported to cause Leigh syndrome or cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysphasia syndrome (CAGSSS). To our knowledge, IARS2 mutations and diseases related to it have only been reported in three families. Here we report a case of two Japanese siblings with Leigh syndrome, some features of CAGSSS, and West syndrome that are found to have compound heterozygous novel IARS2 mutations. CASE REPORT: A 7-month-old Japanese girl presented with infantile spasms. Brain magnetic resonance imaging (MRI) revealed diffuse brain atrophy and hyperintensity in the bilateral basal ganglia. Three years later, her younger sister also presented with infantile spasms. MRI revealed diffuse brain atrophy and hyperintensity of the bilateral ganglia, suggesting Leigh syndrome. The siblings were identified with compound heterozygous missense mutations in IARS2, p.[(Phe227Ser)];[(Arg817His)]. CONCLUSION: This is the first case study reporting Leigh syndrome concomitant with some features of CAGSSS in siblings with novel IARS2 mutations, thereby broadening the phenotypic spectrum of IARS2-related disorders. Further studies are warranted to elucidate the nature of these disorders.
BACKGROUND:IARS2 encodes isoleucine-tRNA synthetase, which is aclass-1 amino acyl-tRNA synthetase. IARS2 mutations are reported to cause Leigh syndrome or cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysphasia syndrome (CAGSSS). To our knowledge, IARS2 mutations and diseases related to it have only been reported in three families. Here we report a case of two Japanese siblings with Leigh syndrome, some features of CAGSSS, and West syndrome that are found to have compound heterozygous novel IARS2 mutations. CASE REPORT: A 7-month-old Japanese girl presented with infantile spasms. Brain magnetic resonance imaging (MRI) revealed diffuse brain atrophy and hyperintensity in the bilateral basal ganglia. Three years later, her younger sister also presented with infantile spasms. MRI revealed diffuse brain atrophy and hyperintensity of the bilateral ganglia, suggesting Leigh syndrome. The siblings were identified with compound heterozygous missense mutations in IARS2, p.[(Phe227Ser)];[(Arg817His)]. CONCLUSION: This is the first case study reporting Leigh syndrome concomitant with some features of CAGSSS in siblings with novel IARS2 mutations, thereby broadening the phenotypic spectrum of IARS2-related disorders. Further studies are warranted to elucidate the nature of these disorders.
Authors: Tian Zhao; Caitlin Goedhart; Gerald Pfeffer; Steven C Greenway; Matthew Lines; Aneal Khan; A Micheil Innes; Timothy E Shutt Journal: Int J Mol Sci Date: 2020-11-06 Impact factor: 5.923