Identification of ARG1 Mutations in Patients with Arginase 1 Deficiency

Abstract

Introduction: Argininemia is an autosomal recessive uncommon metabolic condition, caused by mutations in arginase enzyme. Variable clinical symptoms of argininemia might bring about a delayed diagnosis. In order to prove an argininemia condition, a genetic test result is needed. This study aims to describe two cases of argininemia homozygote mutations. Materials and Methods: Whole exome sequencing (WES) was utilized to detect disease causing variants. To prove adverse impacts of a novel variant and in silico analysis, PROVEAN web server is chosen. The effects of the novel mutation on the enzyme’s structure are shown in Chimera software using normal and mutated structures derived from SWISS model web server. Result: WES revealed two cases of autosomal recessive hyperargininemia. In one of the patients, a homozygous missense mutation of c.491G>A was detected, which is a novel ARG1 variant (p.Trp164Ter). Bioinformatics databases and the variant’s protein structure proved its deleterious effect on the enzyme’s function. The other patient was affected by a reported mutation of c.703G>A (p.G235R). Conclusion: The presence of various types of neurological and metabolic disorders with the same clinical findings with argininemia might lead to a lack of early diagnosis for beginning efficacious treatments. WES provides these patients with the opportunity to become diagnosed and receive therapies as early as possible.