myopathy with myalgia, increased serum creatine kinase, and with or without episodic rhabdomyolysis 1

A muscular disease characterized by the onset of muscle cramping and stiffness on exertion in infancy or early childhood, although later (even adult) onset has also been reported that has_material_basis_in homozygous or compound heterozygous mutation in the ML

A muscular disease characterized by the onset of muscle cramping and stiffness on exertion in infancy or early childhood, although later (even adult) onset has also been reported that has_material_basis_in homozygous or compound heterozygous mutation in the MLIP gene on chromosome 6p12.

Signs and symptoms

• Skeletal muscle atrophy
• Elevated circulating creatine kinase activity
• Centrally nucleated skeletal muscle fibers
• Distal upper limb muscle weakness
• Motor delay
• Increased endomysial connective tissue
• Progressive proximal muscle weakness
• Proximal lower limb muscle weakness
• Increased circulating lactate dehydrogenase concentration
• Muscle fiber necrosis