Childhood neuromuscular disorders: a decade's experience in Saudi Arabia.

The study describes the pattern of childhood neuromuscular disorders seen in a decade (1982-1992) at King Khalid University Hospital, Riyadh, Saudi Arabia. Similar data are scanty outside Europe and North America, and lacking in Saudi Arabia. Eighty-four children (< or = 16 years) were assigned to an entity of neuromuscular disease following review of the clinical, biochemical and neurophysiological data, and after re-examination of the histological and histochemical features of the muscle biopsies. Of the 84 ascertained cases, 40 (48%) had different forms of muscular dystrophy (MD), 26 (31%) had one of the various types of spinal muscular atrophy (SMA) and two (2.4%) hereditary motor and sensory neuropathy type I. The rest were miscellaneous cases including one (1.2%) with dermatomyositis. Of the dystrophies, severe childhood autosomal recessive muscular dystrophy (SCARMD) was more prevalent (30%) than Duchenne type (25%), conforming with observations from North African countries known to have a high incidence of consanguineous marriages. Family history of other cases of SCARMD included three males and three females, one of whom died at 15 years, and consanguinity was evident in 63%. Congenital MD, inherited in an autosomal recessive pattern, was also common (30%). A history of consanguinity was present in 55%. Of the 26 cases of SMA, type I (Werdnig-Hoffman disease) was the most prevalent (69%). Consanguinity was ascertained in 65% of SMA families and histories revealed another 14 affected siblings. Autosomal recessive forms seem to constitute the bulk of neuromuscular disorders in Saudi Arabia.