Tetralogy of Fallot (Cyanotic Cardiac Malformation), trends and variation in a population based study

Congenital heart diseases (CHDs) are a major threat worldwide for children below the age of five. It has high mortality and morbidity ratio. CHDs can be classified as cyanotic and acyanotic. Cyanotic cardiac malformation accounts 25% of all congenital heart diseases and Tetralogy of Fallot (TOF) is the most common form of cyanotic CHD. Tetralogy of Fallot is a combination of four anatomical abnormalities. These include a large ventricular septal defect (VSD), right ventricular outflow tract and pulmonary valve obstruction, right ventricular hypertrophy, and over-riding of the aorta. The current investigation was conducted over the span of 2.5 years on the patients presented in OPD and hospitalized at various pediatric cardiology centers. A detailed family history was taken to elucidate the genetic and environmental factors. Diagnosis was confirmed by the cardiologist based on examination of cardiac murmur, chest X-ray, fetal echocardiography (ECG), complete blood count (CBC), echocardiograms and/or echocardiogram (ECHO) reports, cardiac catherization reports, operative notes and MRI of heart, if applicable. This study recruited a cohort of 268 patients and 140 controls, healthy unrelated individuals. The mean age for patients was 2.97±1.21 and that for controls was 3.14±2.44 years. Males were shown to have a higher rate of incidence than females (1.26: 1) in our population. The genes that are mainly involved are NKX 2.5, GATA 4, TBX5, JAG1, ZFPM2 and VEGF. The present study focuses on NKX 2.5 and its mutations in our population.