INFANTILE SPINAL MUSCULAR-ATROPHY - CURRE NT ASPECTS

Infantile spinal muscular atrophy (ISMA) is a common inherited disease transmitted on an autosomal recessive basis, in which atrophy of the anterior horn cells in the spinal cord is the primary abnormality, Thr ee clinical patterns have been described: (i) in Type I (Werdnig-Hoffm an disease), onset is prior to age six months, the infant is unable to learn how to sit, and the outcome is rapidly fatal; (ii) in Type II ( intermediate form), the infant learns how to sit but not to walk; (iii ) and in Type III (Kugelberg-Welander disease), the child can walk, al beit with difficulty. All three types of ISMA are due to abnormalities of the Survival Motor Neuron gene, which is located in position q12-q 13 of chromosome 5. Studies of genotype-phenotype correlations will pr obably bring new insights into the pathogenesis of ISMA in the near fu ture. Twenty-four cases diagnosed between 1990 and 1995 are reviewed f rom the viewpoint of current findings on ISMA.