A novel mutation in ARG1 gene is responsible for arginase deficiency in an Asian family

Argininemia is a rare autosomal recessive metabolicdisorder caused by a deficiency in the arginaseenzyme, which is the final enzyme in the urea cycleand responsible for the hydrolysis of arginine to ureaand ornithine. The disease becomes symptomaticduring childhood and is characterized by progressivespastic quadriplegia, progressive mental impairment ,growth retardation, and periodic episodes ofhyperammonemia. At least 19 distinct mutations inthe ARG1 gene have been identified indicating themolecular heterogeneity ofthis condition.We report ahomozygous novel mutation (c.93 delG) in theARG1gene from 3 affected children of a Pakistani familyliving in the United Arab Emirates. The mut ation isexpected to lead to a frame shift after the thirti ethresidue and a stop codon at residue 44 (p.T3 0fsXI4) .Therefore, this mut ation is expected to result incomplete loss-of-function of the arginase enzyme andtherefore is the mostly likely cause of argininemia inthis family.