Arginase Deficiency

Alternative Names

• ARG1 deficiency
• Argininemia
• Hyperargininemia

Contact Information

• Phone: 0800 652 3181 (10am-4pm, Monday to Friday)
• Email: [email protected]

Causes

• Arginase Deficiency is a rare inherited metabolic disorder.
• Affects protein breakdown in the body, specifically the conversion of ammonia to urea.
• Lack of enzyme arginase 1 leads to high arginine levels and potentially high ammonia levels.

Prevalence

• Very rare; occurs in 1 in 300,000 to 1,000,000 individuals.

Symptoms

• High arginine can lead to:
  • Spasticity (stiff legs)
  • Learning difficulties
  • Seizures
  • Poor growth
• High ammonia may cause drowsiness or coma, especially during increased protein breakdown (e.g., illness).

Diagnosis

• High blood arginine levels suggest diagnosis.
• Confirmed by identifying ARG1 gene mutation.

Treatment

• Managed with:
  • Protein-restricted diet
  • Amino acid supplements
  • Energy-rich food and feeds
  • Regular feeding
  • Vitamin and mineral supplements
  • Medications to control ammonia
• Emergency regimen during illness:
  • Stop protein intake
  • Start glucose polymer feeds
  • Continue medications
• Close monitoring of blood tests, growth, and development required.

Genetic Information

• Arginase Deficiency is inherited, with carriers having one non-working ARG1 gene.
• 25% chance of having the disorder if both parents are carriers.

Recommendations

• Keep dietary products and emergency feeds in stock.
• Ensure emergency plan is in place.
• Contact metabolic team if symptoms persist or worsen.

Resources

• Visit www.lowproteinconnect.com for support and advice on low protein diets.
• TEMPLE Guides and support by Nutricia, adapted by BIMDG.

References

• Available upon request via phone or email.