A homozygous mutation of alanyl-transfer RNA synthetase 2 in a patient of adult-onset leukodystrophy: A case report and literature review

Abstract

Introduction: Leukodystrophy is a group of hereditary leukoencephalopathies predominantly affecting the white matter. Multiple genes and mutations have been reported to be associated with this disorder. Identification of pathogenic genes can facilitate diagnosis of leukodystrophy and development of therapeutic strategies. Methods: A case was presented with clinical examinations. Exome sequencing was applied to identify potential mutations. Sanger sequencing of blood DNA was applied to confirm the mutation and to examine additional members. Results: We reported a Chinese male patient of adult-onset leukodystrophy. Genetic examinations identified a homozygous mutation, c. 452T>C (p. M151T), in alanyl-tRNA synthetase 2 (AARS2) in the patient. The disease was autosomal recessive as suggested by the genotypic analyses of his family members. We also reviewed phenotypic spectra of AARS2 mutation-associated leukodystrophies from a total of 16 reported cases. Conclusions: Our data provide further evidence that mutations of AARS2 are implicated in adult-onset leukodystrophy.