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Background Kidney diseases are a common cause of secondary hypertension in children, which determines an unfavourable prognosis of the underlying disease. The secondary hypertension is a multifactorial complex disorder caused both by genetic and environmental factors. According to estimations approximately in 30% of cases, the interindividual variability in blood pressure is genetically determined. Numerous studies focused on the role of genetic variation in genes implicated in the renin-angiotensin system (RAS), particularly the angiotensin-converting enzyme (ACE) gene. The purpose of our study was designed to explore association of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with secondary hypertension in a group of children with glomerulonephritis. Methods The study included two groups of children with glomerulonephritis, one of them - hypertensives (cases) and another group - normotensives (controls). Group with hypertension comprised 35 children, age 10.46±2.93 years (20 males and 15 females), group without hypertension included 26 children, age 9.61±3.18 years (18 males and 8 females). The variant genotype of ACE gene (I/D polymorphism; rs4646994) was determined using polymerase chain reaction (PCR). DNA was extracted from blood samples. DNA fragments length analysis after amplification and restriction was carried out in 7% acrylamide gel. Statistical analysis was performed using STATISTICA, version 10.0 StatSoft Inc, USA. Results We determine the distribution of genotype and allele frequencies in the hypertensives and normotensives groups of children with glomerulonephritis. The analysis showed that the frequencies of genotype II, ID, DD of ACE gene in the group of hypertensives were 14.3%, 25.7%, 60%, in the group of normotensives were 76.9%, 15.4%, 7.7%. We found statistically significant higher frequency of DD genotype (χ2 = 8.44; d.f.=1; p=0.004) and D allele (z=6.1; p=0.001) in the hypertensives group in comparison with the normotensives group of children. We calculated the probability of DD genotype detection in the group of patients with glomerulonephritis by the odds ratio (OR) was calculated with 95% confidence interval (95% CI). Patients with the DD genotype had a higher risk of hypertensives than patients with the II, ID genotypes (OR: 18; 95% Cl: 3.66 - 88.55). Conclusions The findings revealed significant influence of I/D polymorphism of ACE gene on hypertension in the groups of children with glomerulonephritis. There are significant associations between DD genotypes and secondary hypertension in children with glomerulonephritis. |
