Werdnig Hoffman's disease (spinal muscular atrophy type I): A clinical study of 25 Saudi nationals in Al-Khobar.

We describe the clinical features of 25 cases of Werdnig Hoffman's disease (spinal muscular atrophy (SMA) type I) seen propectively over a two-year period at the King Fahd Hospital of the University (KFHU), Al-Khobar. The hospital incidence rate was 1.93 per 1,000 live births (95% confidence limits, 0.80-3.06/1,000). The estimated prevalence rate for the community was 0.92/10,000 with 0.59-1.25 per 10,000 children as its 95% confidence limits. The male to female ratio was 2:3. Reduced fetal movements were reported by six mothers; 8 children (32%) had symptoms at birth, and 24 (96%) had symptoms by the time they were six months old. Other features apart from hypotonia, muscle weakness, and absent deep tendon reflexes included head lag with inability to achive head control at six months (88%), respiratory problems consisting of difficulty with breathing or frequent chest infections (44%), and difficulty with feeding (40%). Wasting with fisciculations of the tongue was seen in 64%. Death occurred within six months of presentation in 75% of the cases. The parents were consanguineous in 64% of the cases. This high consanguinity rate was probably the major cause for the high population prevalence rate.