Rationale: Chagas disease is a complex disorder caused by Trypanosoma cruzi. Most patients remain asymptomatic for several years and 30% of them progress quietly to developing cardiomyopathy. The factors that lead to chronic myocardial lesions are not fully understood.

Objective: To investigate the association between clinical symptoms and single nucleotide polymorphisms in chagasic and non-chagasic women younger and older than 55 years of age.

Methods and Results: we analyzed Ala-9Val and Ile58Thr polymorphisms of the SOD-Mn gene, 138ex1ins/del A of the endothelin-1 gene (ET-1) and H323H (T/C) of the endothelin receptor A gene (ETA), by PCR-RFLP using genomic DNA from leukocyte of 85 women. We also evaluated serum lipid profile, renal and liver function, chest X-rays, electrocardiograms (ECGs) and echocardiography (EchoCG). Biochemical profiling did not show differences between chagasic and non-chagasic patients. The polymorphisms analyses showed a significant association in the distribution of frequencies of the Mn-SOD Ile58Thr gene between both groups. Young chagasic patients had a significantly higher prevalence of abnormalities in X-rays, in ECGs and they showed grade II and III of NYHA functional classes. The chance of having an abnormal EchoCG was 5.87 higher in young chagasic patients (OR=5.87, 95% CI 1.47-23.4).

Discussion: We concluded that the parasite affects young females by accelerating the deterioration of cardiac function, independent of other cardiovascular risk factors and the cardioprotective action of estrogens present in the premenopausal stage.