Cerebral MRI in two brothers with mucopolysaccharidosis type I and different clinical phenotypes

Abstract
We describe a cerebral MRI study of two brothers with mucopolysaccharidosis type I. They are of similar physical appearance, but the younger is severely mentally retarded while the elder is of normal intelligence. MRI shows characteristic abnormalities in the CNS, but it is not yet possible to establish a correlation between them and the mental retardation.