Value of radiological follow up of childhood pneumonia.

Abstract

<h3>Introduction:</h3> Previously we suggested that the <i>CHRNA7</i> polymorphism in nicotinic receptor genes, in particular the D15S1360 in <i>CHRNA7</i>, is associated with smoking in schizophrenia. Schizophrenia patients are usually heavy smokers. In this study we hypothesized that high-affinity nicotinic receptors are associated with smoking in such patients. <h3>Objective:</h3> To investigate the role of α4 (Ch 20) and β2 (Ch 1) genes in conferring a risk for smoking and for smoking a large number of cigarettes daily in subjects with schizophrenia. <h3>Methods:</h3> Our study sample consisted of 241 white European schizophrenia patients (157 smokers and 84 nonsmokers) from the Toronto area. Current smoking status was assessed by the medical history. We investigated 4 markers located in the <i>CHRNA4</i> gene and 3 markers located in the <i>CHRNB2</i> gene. <h3>Results:</h3> There was no difference in age or ethnicity between the 2 groups and the population was not stratified (λ = 0.4527). We found a significant association between the <i>CHRNA4</i> rs3746372 allele 1 and a large number of cigarettes smoked daily (<i>p</i> = 0.0203). The intragenic interaction between rs3787116 and rs3746372 (<i>p</i> = 0.0050) in <i>CHRNA4</i> showed a significant interaction for the number of cigarettes smoked. <h3>Conclusion:</h3> Although our findings suggest an association between rs3746372 allele 1 and heavy smoking, further study is warranted to investigate the relation between smoking and high-affinity nicotinic receptor genes in schizophrenia.