Arginase deficiency (ARG)

Arginase deficiency (ARG) is an inherited disorder that causes the amino acid arginine (a building block of proteins) and ammonia to accumulate gradually in the blood.

Arginase deficiency usually becomes evident by about the age of 3. It most often appears as stiffness, caused by abnormal tensing of the muscles, slow growth patterns, developmental delays, intellectual disabilities, seizures, tremors, and difficulty with coordination.