Molecular analysis of Spanish patients with AMP deaminase deficiency

We found six patients with AMPD deficiency in muscle who were homozygous fo r the most common mutation, Q12X in the AMPD gene (AMPD I), associated with this disease. Th ree patients had AMPD deficiency alone, showing a mild cl inical phenotype, Two patients showed a defect of PPL in muscle, and were h omozygous for the most common mutation associated with McArdie's disease, R 49X in the muscle PPL gene (PYGM). In one of these patients, the clinical p henotype was more severe than usually seen in patients with McArdle's disea se. The remaining patient harbored the mtDNA A3243G mutation, showing one o f the usual clinical patterns associated with this mutation. We conclude th at the Q12X mutation in AMPD1 may result in a mild clinical effect; that it is frequent in the Spanish population, and therefore frequently associated with other metabolic diseases; and that the effect of the association of A MPD and PPL deficiencies seems to be neutral. (C) 2000 John Wiley & Sons, I nc.