Also known as: arginase deficiency; arginase deficiency disease; ARG1 deficiency; ARG

(OMIM#207800)

1. The disease

Argininemia (ARG) is a condition that causes harmful amounts of arginine and ammonia to build up in the body. It is also called ARG or one of the urea cycle disorders, which causes ammonia to accumulate in the body, and even is considered an amino acid condition because people affected with ARG are unable to break down an amino acid, a small molecule that makes up proteins, known as arginine.

2. The symptoms

Infants are initially asymptomatic at birth and during the neonatal period. Symptoms develop within the first two years of life, often between 6 months and 1 year of age. If untreated, argininemia can cause muscle problems and developmental delay. However, if the condition is detected early and proper treatment is initiated, individuals with argininemia can often have healthy lives. Lack of early signs or symptoms does not exclude the diagnosis.

3. Actions to take in case of early diagnosis

  • Infants with a positive genetic test should continue breastfeeding. Early treatment, with a special diet and ammonia scavengers, is essential in preventing chronic symptoms.
  • Biochemical correlation is essential for confirming diagnosis with plasma quantitative amino acid, ammonia levels and urinary organic acids.
  • Argininemia is a lifelong disease that requires lifetime management and regular follow-up with a metabolic physician and a multidisciplinary approach to care.
  • Genetic counseling is highly recommended for family planning and evaluation of at-risk family members such as siblings.

4. More informations