Abnormal signals in basal ganglia of 4 patients of 129Met/Met homozygote occurred after 2.5 months averagely, they survived for 10.5 months at average.

• 4例甲硫氨酸纯合型 (12 9Met/Met)底节T2 异常信号发现时间平均 2 5个月 ,存活时间平均 10 5个月 ;