We describe two siblings, a girl and a boy, aged 4 and 2 years and 10 months respectively, born from non-consanguineous parents,with diffuse polymicrogyria, lower limb deformities, infantile spasms and developmental delay. Spasms had a good outcome under antiepileptic drug treatment. Clinical and imaging features were of identical severity in both siblings. Muscle biopsy,creatine kinase, metabolic investigations and chromosomal analysis were normal. This combination of anatomo-clinical features and their occurrence in siblings of both sexes suggests an autosomal recessive malformation syndrome.