Prevalence of 4a/4b polymorphic variants of the eNOS gene introne in patients with different types of encephalopathies

Questions related to the disruption of vasoregulatory processes as essential factor in neurological pathology require further study. The leading role in the vasoregulatory mechanisms is played by endothelial NO synthase which gene has 15 allelic variants. Recent data indicated a probable association between eNOS gene polymorphism and cerebrovascular diseases. The aim of the present work was to study the prevalence of the 4a/4b introne polymorphism of the eNOS gene in patients with various types of encephalopathies and to evaluate the influence of a particular genotype of the studied gene on the occurrence and/or progression of encephalopathy. A total of 96 patients with encephalopathies of various genesis: chronic traumatic encephalopathy, chronic alcohol-induced encephalopathy, chronic vascular encephalopathy, post-infectious encephalopathy were involved in the study. The patients received inpatient treatment in the neurological department of “Ternopil Regional Clinical Psychoneurological Hospital”. Molecular and genetic differentiation of the studied gene variants was carried out by allele-specific PCR or PCR-restriction fragment length polymorphism analysis by standard operational protocols. Analysis of the frequency distribution of eNOS gene 4a/4b polymorphic variant showed that 4b allele prevailed among patients with all types of encephalopathies carriers­. Relative to practically healthy individuals the difference was found only in patients with chronic vascular encephalopathy (CVE), among whom about 39% were carriers of the 4a allele. The presence of the 4a allele was shown to increased the risk of CVE occurrence and/or progression by 4.5 times. The results obtained suggest the reasonability to include the 4a/b intron polymorphism of the eNOS gene in a genetic panel to monitor patients CVE. Keywords: 4a/4b introne, encephalopathies, endothelial NO-synthase, eNOS gene polymorphism