Clinical and neuroradiological follow-up in mucopolysaccharidosis type III(Sanfilippo syndrome)

Mucopolysaccharidosis type III (Sanfilippo syndrome) is an autosomal recess ive disorder characterised by progressive nervous system involvement with m ental retardation, behavioural problems and seizures. Three patients, of 20 months to 12 years of age, were followed up for 3 years both clinically an d by using brain magnetic resonance imaging (MRI), Our results suggest that in MPS III patients MRI findings, including atroph y and abnormal or delayed myelination, may precede the onset of overt neuro logical symptoms. The increasing neurological morbidity is accompanied by d ifferent degrees of progressive atrophic changes. mainly affecting the cere bral cortex and the corpus callosum. However, it appears that, across subje cts, the rate of MRI changes is unrelated to the severity of the clinical p henotype. On this basis it could be argued that in MPS III the worsening of the neurological symptoms might not necessarily reflect only the progressi ve cerebral abnormalities detectable by MRI.