EXCLUSION OF THE GENE LOCUS FOR SPINAL MUSCULAR-ATROPHY ON CHROMOSOME5Q IN A FAMILY WITH INFANTILE OLIVOPONTOCEREBELLAR ATROPHY (OPCA) ANDANTERIOR HORN CELL DEGENERATION

Two sisters with infantile OPCA plus spinal muscular atrophy (SMA) are reported. Both showed severe hypotonia and psychomotor delay from bir th, and in addition, nystagmoid eye movements and vision impairment we re evident. Cerebellar hypoplasia with cystic dilatation was seen by n euro-imaging methods. Pathoanatomically, a marked cerebellar hypoplasi a and neuronal loss in the basal ganglia, brainstem and anterior horns were found in the deceased girl. Linkage studies with polymorphic mar kers of the region 5q11.2-q13.3 flanking the gene locus for infantile SMA showed identical parental haplotypes in the patients and their old er healthy sister. It can be concluded that the gene locus for infanti le SMA on chromosome 5q is not responsible for infantile OPCA plus ant erior horn cell degeneration in the described family which might apply to this disorder in general.