The Association Between Polymorphism Of Monoamine Oxidse A Gene With The Genetic Suspectibility To Hypertensive Disorder Complicating Pregnancy

Objective: Hypertensive disorder complicating pregnancy (HDCP)is a syndrome characterized by hypertension, proteuria, hydrosarca and often leads to damage of many organs that occurs after 20 weeks of gestation. It is a leading cause of both maternal and fetal morbidity and mortality worldwide. The morbility are 9.4% and 7% to 12% respectively home and abroad. It is one of the areas of clinical practice that has been studied about etiopathogenesis and pathological changes extensively, yet less well understood. Recent years, many scholars have been studying some predisposing genes of the onset of HDCP.Monoamine oxidase (MAO; monoamine: oxygen oxidore- ductase; EC1.4.3.4) catalyzes the oxidative deamination of a number of biogenic amines in the brain and peripheral tissues by the production of hydrogen peroxide (H2O2). It is an enzyme expressed in the outer mitochondrial membrane. On the basis of substrate selectivity and inhibitor sensitivity, two forms of MAO were proposed and designated MAO-A and MAO-B. Studies indicat the level of CA especially NE is higher in HDCP patients than in normol pregnant women. The high level of CA is one of the reason of arteriospasm in HDCP patiens. The circulating CA, especially NE has a intensive role of vasocons- triction and increases peripheral resistance and blood pressure, even induces proteuria. MAO-A is the main catabolic enzymes in the metabolic process of CA. Its activity impacts the content of CA, MAO-A is possibly to result in the HDCP directly or indirectly. Because the activity of MAO-A is determined by genetic factor, so the polymorphism of coding gene is possibly related to the genetic predisposition of HDCP. Polymorphisms of the MAO-A gene have been use to study its association with several psychiatric conditions and nervous system diseases, such as BPD, depression, aggression-related traits, and PD. But the relevant researches between MAO-A polymorphism and the susceptibility of HDCP haven't been seen worldwide.In this experiment, we used polymerase chain reaction- restriction fragment length poltmorphism (PCR-RFLP) to detect the genotype of MAO-A gene EcoRV restriction site which come from HDCP patients and normal controls. The aim of the current study is to examine whether this polymorphism can influence the risk for HDCP patients, which issue none of the earlier studies dealt with.Methods: This population-based case-control study includes 45 HDCP patients and 60 healthy pregnant woman controls. Collecting their vein anticoagulated blood, at the same time, noting their case history, history of past illness, the individual-correlated data and so on. Genomic DNA was extracted by using the kit of extracting DNA. Polymorphisms of MAO-A gene EcoRV restriction site(C/T) were detectde by PCR-RFLP and analyzed with HDCP.Statistical analysis was performed using SPSS11.5 software package. P<0.05 was considered significant for all statistical analyses.Hardy-Weinberg analysis was performed by comparing the observed and expected genotype frequencies distribution in the HDCP patients and control group. Comparison of the age and gestational weeks in HDCP patients and healthy controls was perpormed by t test. Comparison of the genotype and allelotype distributions in HDCP patients and healthy controls were performed by Chi-square test. At the same time, the odds ratio (OR) and 95% confidence Interval (CI) were calculated.Results:1 General characteristics of the object The case group comprised 45, the mean age 28.13±3.83Y, mean gestational weeks 37.90±1.17W. The normal controls comprised 60, the mean age 61.60±12.10Y, mean gestational weeks 37.90±1.17W. There were no significant differences in the age between two groups (t=1.112 p=0.269)(see Table 1), and in the gestational weeks between two groups (t=-1.945 p=0.055)(see Table2).2 The relationship between genotype of MAO-A gene EcoRV restriction site and HDCPMAO-A gene EcoRV restriction site allele and genotype frequency distributions were consistent with Hardy-Weinberg analysis between two groups(P>0.05). The frequencies of C/C, C/T and T/T genotypes of the MAO-A gene EcoRV restriction site were 24.4%, 44.4% and 31.2% in HDCP group, respectively. They were 23.3%,43.3% and 33.4% in normal control group, respectively. The genotypic frequency of C/C C/T was higher than controls, also allele C frequency of HDCP was higher than controls, 46.7%vs45.0%, but There were no significant differences in them(χ2=0.060 P=0.971;χ2=0.058 P=0.810). The results of relative risk analysises of MAO-A genotypes distribution and alleles showed that genotypes C/C and C/T didn't increase the risk of HDCP in our study, or C allele did neither.Conclusions:1 Our study aimed to examin the relationships of poly- morphism of MAO-A gene EcoRV(C/T)restriction site and genetic susceptibility of HDCP first time.2 There is no significant difference about the allele and genotype frequencies of MAO-A gene EcoRV restriction site between case group and normal controls . Our results show that MAO-A gene EcoRV restriction site perhaps can't increase the risk of HDCP.3 In our study, the allele C of MAO-A EcoRV(C/T) restriction site don't increase the risk of HDCP.