Multiminicore disease (MmD) is a clinically heterogeneous condition in which several subgroups can be distinguished (see 255320 and 602771). General features include neonatal hypotonia, delayed motor development, and generalized muscle weakness and amyotrophy, which may progress slowly or remain stable. Muscle biopsy shows multiple, poorly circumscribed, short areas of sarcomere disorganization and mitochondria depletion (areas termed 'minicores') in most muscle fibers. Typically, no dystrophic signs, such as muscle fiber necrosis or regeneration or significant endomysial fibrosis, are present in multiminicore disease (Ferreiro and Fardeau, 2002). [from
OMIM]