Mondo Description A benign form of phosphorylase kinase deficiency caused by variants in PHKA1, characterized by exercise intolerance, myalgia, muscle cramps, myoglobinuria, and progressive muscle weakness.

Uniprot Description A metabolic disorder characterized by slowly progressive, predominantly distal muscle weakness and atrophy. Clinical features include exercise intolerance with early fatigability, pain, cramps and occasionally myoglobinuria.