MOLECULAR EPIDEMIOLOGY OF APOLIPOPROTEIN E AND VITAMIN D RECEPTOR IN NORTHERN PART OF KYOTO PREFECTURE

PCR-RFLP方法广泛应用于载脂蛋白E （ApoE）基因型的检测。然而，用PCR-RFLP方法检测ApoE杂合型存在一些问题。当使用最常用的PCR引物时，限制性内切片段的密度取决于基因的基因型。此外，用PCR直接测序检测ApoE杂合模式也存在一些问题。我们制备了新的检测ApoE基因型的PCR引物。经PCR扩增后，采用RFLP法和直接测序法确定载脂蛋白基因型。使用新引物时，酶切后的片段密度相同，直接测序容易鉴定杂合模式。结果表明，新引物对ApoE基因型的检测比普通引物更可靠。利用这些引物对京都县北部地区进行了ApoE基因型分析。研究对象为198名65岁及以上的城镇居民，21名住院老人。这219人被分为三组；无痴呆组183例，老年痴呆（SDAT）组22例，血管性痴呆组14例。无痴呆组ApoE2/2、3/3、2/4、3/4、4/4的频率分别为1.1%、5.5%、75.4%、1.1%、16.4%、0.5%，SDAT组为0%、0%、77.2%、4.5%、18.2%、0%。epsilon 4的频率在无痴呆组为9.3%，在SDAT组为11.4%。SDAT组epsilon 4频率高于无痴呆组，但差异无统计学意义。到目前为止，该地区痴呆组的epsilon 4频率没有比日本其他地区高，但这种差异也不显著。

The PCR-RFLP method is widely used for detecting genotypes of Apolipoprotein E (ApoE). However, there are some problems to detect the heterozygous pattern of ApoE by PCR-RFLP method. When the most popularly used PCR primers were employed, the density of restriction fragments vary depending on genotypes of the gene. Also, there are some problems to detect heterozygous pattern of ApoE by direct sequencing with PCR.We prepared new PCR primers for detecting genotypes of ApoE.After amplification by PCR,genotypes of Apolipoprotein were determined by RFLP method and direct sequencing. When the new primers were used, density of fragment after digestion by restriction enzyme was identical and heterozygous pattern was easily identified by direct sequencing. These results indicated that the new primers were more reliable for detecting genotypes of ApoE than ordinal primers.We performed the genotype analysis of ApoE in the northern part of Kyoto Prefecture using these new primers for ApoE.Subjects were 198 residents 65 years old and older in the town, 21 eldely in a hospital. These 219 persons were divided into three groups ; no dementia group 183, senile dementia of Alzheimer type (SDAT) group 22 and vascular dementia group 14. The frequencies of ApoE2/2,3/3,2/4,3/4,4/4, were 1.1%, 5.5%, 75.4%, 1.1%, 16.4%, 0.5% in no dementia group and 0%, 0%, 77.2%, 4.5%, 18.2%, 0% in SDAT group. The frequencies of epsilon 4 were 9.3% in no dementia group and 11.4% in SDAT group. The frequency of epsilon 4 was higher in SDAT group than no dementia group, but this difference was not statistically significant. The frequency epsilon 4 in no dementia group in this area was higher reported so far from other Japanese areas, but this difference was not significant, either.