散发性阿尔茨海默病早老素2 基因的新突变

 目的检测早老素2（PSEN2）基因的外显子序列，探索基因外显子可能的突变与散发性阿尔茨海默病（SAD）发
病的相关性。方法所有被试者均来自日本人群。选择300 例符合NINCDS-ADRDA诊断标准的无阳性家族史的SAD 患者，其
中男120 例，女180 例，平均年龄（72.57±7.56）岁。选择与患者组年龄、性别相匹配的正常对照300 例，其中男120 例，女180 例，
平均年龄（70.97±6.73）岁。从被试者外周血中提取基因组DNA，采用聚合酶链式反应、DNA测序方法，进行基因外显子
序列测定。结果PSEN2基因外显子3上发现100G>A（G34S）的突变， 基因外显子4 上发现1915C>T（87H）的突变。结
论此次发现的2个基因突变均位于PSEN2 蛋白非功能区N 端片段，可能与SAD发病无关。

Association of Mutations of Presenilin-2 Gene and Sporadic Alzheimer's Disease

Objective To detect exon sequences of presenilin-2 gene （PSEN2），and to explore the association between possible muta-
tions of PSEN2 gene and sporadic Alzheimer's disease（SAD）. Methods All subjects were from Japan. We examined 300 SAD patients
without family history（120 males and 180 females，average age 72.57±7.56 years），along with an equal number of age-and sex-matched
controls （average age 70.97±6.73 years）. The diagnosis of Alzheimer's disease was made according to NINCDS-ADRDA criteria. Genomic
DNA was extracted from blood of patients and controls. PSEN2 gene exon sequences were determined by polymerase chain reaction and DNA
sequencing. Results We found point mutation of 100G>A （G34S）on exon3 and that of 1915C>T （87H）on exon4. Conclusion The
two point mutations were on the N-terminal fragment in the non-functional region of presenilin-2 protein，so they may not be related to SAD.