Myoadenylate deaminase deficiency. A common inherited defect with heterogeneous clinical presentation.

Myoadenylate deaminase deficiency is a clinically heterogeneous metabolic disorder that is commonly diagnosed in a variety of neurologic settings. Although the molecular basis for this purine nucleotide catabolic derangement may typically be attributed to the inheritance of a single prevalent mutant allele, the clinical spectrum in the absence of other definable abnormalities can range from asymptomatic to mild exercise-induced myalgia. Moreover, myoadenylate deaminase deficiency is also found associated with other definable neuromuscular disorders. The myoadenylate deaminase deficiency in these latter cases may, in part, be precipitated by pathologic change or act synergistically in combination with another metabolic disease.