Bethlem myopathy 1A

A Bethlem myopathy that has_material_basis_in heterozygous mutation in the COL6A1 gene on chromosome 21q22.

Signs and symptoms

• Difficulty climbing stairs
• Fatty replacement of skeletal muscle
• Fiber type grouping
• Macroscopic hematuria
• Proximal muscle weakness
• Centrally nucleated skeletal muscle fibers
• Proteinuria
• Muscle fiber necrosis
• Elbow contracture
• Motor delay