Polymorphism Of Angiotensin Converting Enzyme Gene And Vascular Dementia

Objective To explore the relationship between the polymorphism of the angiotensin converting enzyme (ACE) gene and vascular dementia (VD).Methods 94 cases of VD, 60 cases of essential hypertension and 60 cases of healthy controls were chosen in the study. Peripheral blood was taken from all the subjects, and DNA was extracted by using DNA extracting kit. An insertion/deletion polymorphism of the ACE gene was analyzed by polymerase chain reaction (PCR). Only 490bp band on e-lectrophoresis represented I/I type of ACE gene, and only 190bp band represented D/D type of ACE gene, and both 490bp and 190bp bands represented I/D type of ACE gene.Results (1)Among 94 cases of VD,there were 33 cases belonging to DD genotype (35.11%),45 cases belonging to DI genotype (47. 87%), and 16 cases of II genotype (17. 02%);The frequency of D and I allele was 59. 04% and 40. 96% respectively. In 60 cases of healthy controls, there were 10 cases of DD genotype (16. 67%),28 cases of DI genotype (46. 67%),and 22 cases of II genotype(36. 66%) ; The frequency of D and I allele in this group were 40. 00% and 60. 00% respectively. So both the DD genotype and the frequency of D allele of VD cases were significantly higher than that of normal healthy controls (x2 = 10. 212, 10. 657; P<0. 01, P<0. 01). (2)In 85cases of VD occurred after cerebral stroke, there were 31 cases of DD genotype (36. 47%), 41 cases of DI genotype (48. 24%), 13 cases of II genotype(15. 29%),and the frequency of D and I alleles was 60. 59% and 39. 41% respectively. In the 9 cases of VD that were not caused by cerebral stroke,there were 2 cases of DD genotype(22. 22%) ,4 cases of DI genotype(44. 44%),and 3 cases of II genotype(33. 34%); and the frequency of D and I alleles were 44. 44% and 55. 56% respectively. These results showed that both the DD genotype and the frequency of D allele in the VD cases caused by cerebral stroke were higher than that of the VD cases who were not caused by cerebral stroke. However statistical test was not done because of the limited subjects. (3) Among the 58 cases of VD with EH, there were 24 cases belonging to DD genotype(41. 38%),28 cases belonging to DI genotype(48. 28%), and 6 cases belonging to II genotype(10. 34%); and the frequency of D and I alleles were 65. 52% and 34.48% respectively. While in the 36 cases of VD without EH,there were 9 cases of DD genotype (25. 00%), 17 cases of DI genotype (47. 22%), and 10 cases of II genotype(27. 78%); and the frequency of D and I alleles were 48. 61% and 51. 39% respectively. Compared with the cases of VD without EH, both the DD genotype and frequency of D al-lele of the VD cases combined with EH were higher(x2 =6. 777, 7. 250,P<0. 05). (4)The clinical conditions of VD cases were not associated with the polymorphism of the ACE gene.Conclusions There was significant relationship between polymorphism of the ACE gene and VD ;DD genotype and D allele of ACE gene could not only relate directly to VD but also promote the occurrence of VD by enhancing the emergency of the risk factors of VD, such as cerebral stroke, hypertension, and so on.