[Clinical analysis of late infantile form of muscular atrophy].

Clinical analysis of 47 cases of late infantile spinal muscular atrophy is reported. In 25.5% of cases mothers reported weak fetal movements in pregnancy and low muscular tonus after birth, these signs predicted early manifestation of the disease. In 89,2% of cases the first signs of the disease appeared within the first 3 years of life. Delayed motor development in infancy was observed in 59.6%. Immobilization developed between the ages of 2 and 18 years, usually after 7 years of disease duration, and it was not correlated with the age of onset of the first signs of the disease. Mental development was normal in 81.5% of cases. Familial character of the disease was found in 51.1% of cases and in some of them intrafamilial variability was observed.