[Three siblings with type 3 GM1-gangliosidosis--pathophysiology of dystonia and MRI findings].

GM1-gangliosidosis is a rare neurovisceral storage disease caused by an inherited deficiency of acid beta-galactosidase. The characteristic neurological feature of type 3 (adult or chronic) GM1-gangliosidosis is usually a slowly progressive dystonia with dysarthria due to predominant involvement of basal ganglia. About 20 adult patients with this disorder have been reported in the literature. However, there are no reports of 3 brothers with type 3 GM1-gangliosidosis, and MRI findings. Case 1 (proband): A 28-year-old man was hospitalized because of facial grimace, dysarthria, and generalized dystonia. He was born after normal pregnancy and delivery. His development was normal until 3 years of age when the difficulties of speaking and walking were noticed by his parents. These neurological abnormalities progressed slowly and facial grimace and dystonic movements occurred 7 years later. He could not walk at 22 years of age. On admission, he was bedridden with marked scoliosis and subluxation of the mandibule. The communication was possible only by pointing the words written on the board. Case 2: A 33-year-old man, elder brother of case 1, showed the similar neurological features and clinical course. Slit-lamp examination revealed corneal opacities which were located in the deep stroma. Case 3: A 33-year-old man, elder brother of case 1 or case 2. At age 10-11, he noted similar symptoms as case 1 or case 2. The severity of dystonia was milder than his brothers. A diagnosis of GM1-gangliosidosis in three patients was made on the basis of the following data.(ABSTRACT TRUNCATED AT 250 WORDS)