congenital myopathy 1B

A congenital myopathy that is characterized by multiple areas of reduced mitochondrial oxidative activity running along a limited extent of the longitudinal axis of the muscle fiber, so-called 'minicores' and that has_material_basis_in homozygous or compound h

A congenital myopathy that is characterized by multiple areas of reduced mitochondrial oxidative activity running along a limited extent of the longitudinal axis of the muscle fiber, so-called 'minicores' and that has_material_basis_in homozygous or compound heterozygous mutation in the RYR1 gene on chromosome 19q13. Multiminocore disease is broadly classified into four groups: classic form, moderate form with hand involvement, antenatal form with arthrogryposis multiplex congenita, and ophthalmoplegic form.

Signs and symptoms

• Motor delay
• Minicore myopathy
• Skeletal muscle atrophy
• Centrally nucleated skeletal muscle fibers
• Generalized muscle weakness
• Respiratory insufficiency
• Neonatal hypotonia
• Increased variability in muscle fiber diameter
• Hypotonia
• Feeding difficulties in infancy

Also known as: autosomal recessive congenital myopathy 1B; multiminicore disease