AMP deaminase is widely distributed in various mammalian cells and tissue-specific isozymes were found. Muscle specific AMP deaminase is also known as myoadenylate deaminase (MAD). MAD deficiency (MADD) was discovered in patients with muscle weakness and cramping after exercise, and the mutations in AMP deaminase gene (AMPD1) have been identified. Although a point mutation on the human erythrocyte AMPD3 has also been identified, erythrocyte AMP deaminase deficiency was clinically asymptomatic.
Myoadenylate deaminase deficiency with progressive muscle weakness and atrophy caused by new missense mutations in AMPD1 gene: case report in a Japanese patient.
