Sanfilippo syndrome type C: a clinicopathological autopsy study of a long-term survivor.

A 39-year-old Japanese woman with Sanfilippo syndrome type C is reported. Developmental delay was observed during infancy and progressive intellectual deterioration became apparent at 2 years. Her gait became unsteady and she became bed-ridden at 22 years of age. An intestinal fistula was made because of pyloric stenosis possibly caused by accumulation of mucopolysaccharide at 37 years of age. She died of acute cardiac failure at age 39 years. Pathological changes were marked in the heart and brain. Focal necrosis of myocardial fibers with replacement fibrosis and many vacuolated cells were observed between the muscle fibers and there were many vacuolated cells in the pyloric ring. There was severe neuronal loss with gliosis and massive corpora amylacea formation in the cerebral cortex, especially in layers 2 and 3. Ballooning of neurons was less prominent than neuronal loss. There were many vacuolated cells in the mesenchymal tissues; however, this finding was much less prominent than in other types of mucopolysaccharidosis. Our patient survived much longer than others with Sanfilippo syndrome type C of similar severity.