Molecular Biological Approach to Find Out the Etiology of Hypertensive Disorder in Pregnancy: Analysis of the Polymorphism in the Promoter of Human Angiotensinogen Gene in Korean Population

Shim, Soon Sup; Shim, Jae Yoon; Lim, June Hee; Park, Joong Shin; Jun, Jong Kwan; Bai, Kwang Bum; Yoon, Bo Hyun; Syn, Hee Chul

Abstract

OBJECTIVE
We undertook this study to find out general characteristics of hypertensive disorder in pregnancy and to clarify whether polymorphic marker of promoter region of angiotensinogen G(-6)A polymorphism is associated with the development of hypertensive disorder in pregnancy.
METHODS
From August 1998 to March 2002, we recruited 230 pregnant women complicated by hypertension in pregnancy. Retrospective chart review was done. They were assigned to each group according to a new classification. Hypertensive groups were divided into two groups: high blood pressure group (High) was defined as having diastolic blood pressure (DBP) higher than 110 mmHg and low blood pressure group (Low) as having DBP lower than 110 mmHg. Maternal blood was collected and DNA was extracted from 161 normotensive and 200 hypertensive Korean pregnant women. Genomic DNA was prepared and the relevant genomic region was amplified using polymerase chain reaction (PCR). PCR products were digested with the restriction enzyme, Mva I, size fractionated on 3% agarose gels containing ethidium bromide.
RESULTS
Family history of hypertension was more common in women with chronic hypertension or superimposed preeclampsia than in women with transient hypertension or preeclampsia (p<0.05). No significant difference in genotype distribution was found between diagnostic groups and control. However, among hypertensive disorder in pregnancy, high blood pressure group had AA genotype more frequently than low blood pressure group (p<0.05).
CONCLUSION
Family history is more common in women with underlying hypertension. Angiotensinogen AA genotype may be associated with high blood pressure level in hypertensive disorder in pregnancy.