脊髓小脑变性通常是一遗传性神经系统疾病。病因始终未明,病程为进行性。推测本病有中枢神经系统代谢障碍。本文报告2例成年姊妹脊髓小脑变性。2姊妹均无儿女;另3个姊妹和2个兄弟均有孩子。父母不同血缘。2姊妹在胎儿期、分娩过程和童年生活均无异常。2例均在20岁以后出现进行性步态和亩语障碍,包括明显的构音困难,眨眼,脸和臂有多变的舞蹈动作,手和手指轻度快相震颤,静止时头摇摆。肢体呈弥漫性无力。无癫痫发作和智能减退。根据生化研究有血清和白细胞已糖胺酶 A、B 活性的明显降低和皮肤活检所见,作者认为本病是一成年型 GM_2(单涎脑酰胺三己糖甙)神经节甙脂沉积病。作者指出,一种或多种已糖胺酶不足的 GM_2神 Spinocerebellar degeneration is usually a hereditary neurological disease. Etiology is not yet clear, the course of the disease. Presumably the disease has central nervous system metabolic disorders. This article reports 2 adult sisters spinocerebellar degeneration. 2 sisters have no children; the other 3 sisters and 2 brothers have children. Parents different blood. 2 sisters in the fetal period, childbirth and childhood life are normal. Both of them presented progressive gait and mu language disorder after the age of 20, including obvious dysarthria, blinking, varied dance movements on the face and arm, tremor in the hands and fingers with a mild fast phase, and swaying at rest. Body was diffuse weakness. No seizures and intellectual decline. According to biochemical studies have serum and leukocyte glycosaminoglycans A, B activity was significantly reduced and skin biopsy seen, the authors believe that the disease is an adult GM 2 (mono-sialyl pentahexose glycoside) ganglioside deposition disease. The authors point out that one or more GM2-deficient glycosaminoglycans are deficient