Episodes of low blood sugar. Muscular symptoms may be delayed until early teens and adulthood. Generalized muscle weakness, flaccid neck muscles and inability to walk. Brain is often involved, with seizures, deafness, loss of balance and vision, and retardation common. Varied weakness of shoulders, hips, face and neck muscles.
Progression varies and carnitine supplementation is often effective.
Inability to sustain moderate prolonged exercise. Avoid intense exercise. X-linked recessive, autosomal recessive. Avoid intense exercise. Exercise intolerance with muscle damage and urine discoloration possible following strenuous physical activity.