Clarke et al. (2005) reported a 4-generation Australian family in which at least 7 males had marked congenital muscle weakness inherited in an X-linked pattern. All presented at birth with bilateral ptosis, facial weakness, poor suck, weak cry, ... Clarke et al. (2005) reported a 4-generation Australian family in which at least 7 males had marked congenital muscle weakness inherited in an X-linked pattern. All presented at birth with bilateral ptosis, facial weakness, poor suck, weak cry, generalized hypotonia, and respiratory insufficiency. Six infants died of respiratory failure between the 6 and 14 weeks of age; only 1 survived to age 5.5 years at the time of the report. The survivor had facial weakness and mild generalized limb weakness, but could walk fast, jump, and did not demonstrate Gowers sign. He also showed dilated cardiomyopathy. Serum creatine kinase and lactate were normal. Muscle biopsy showed fiber-type disproportion with type 1 fibers at least 12% smaller than type 2 fibers. Obligate female carriers showed mild muscle weakness and facial weakness, particularly of the frontalis muscle.