Onset at birth. Clinical features include
congenital muscular dystrophy, neonatal muscle weakness with orthopedic
signs (protrusion of calcaneus, clumsy gait, multiple neonatal proximal
joint contractures, limited spine motion, hyperextensible distal joints, hip
dislocation). Other signs are less frequent and can include hyperhidrosis
and high-arched palate. Insufficient cellular immunity has been reported,
which may contribute to the recurrent upper respiratory tract infections and
pneumonia often observed.