Frequency of Congenital Heart Defects in Indian Children with Down Syndrome

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CongenitalHeart Diseases (CHD) are commonly associated with Down Syndrome (DS) infants. Our study aimed at determining the occurrence and pattern of CHD in association with DS among patients in Indian subjects. A total of 60 patients with clinical features suggestive of DS were recruited. Echocardiography, standard karyotype and QF-PCR (Quantitative – Flourescent PCR) studies were performed in all patients in order to confirm DS. CHDs were detected in the 50% of children with DS. The commonest type of CHD reported in Indian subjects was atrioventricular septal defect (50%). The second most type of CHD present was ventricular septal defect (26.6%). Other type of CHD included in our study was atrial septal defect, tetralogy of fallot and patent ductus arteriosus with the frequency of 10 %, 6.6 % and 6.6% respectively. Our findings showed that CHDs are common in Indian DS children. These results suggest that a routine echocardiography should be mandatory in DS patients.

Down Syndrome (DS) or trisomy 21 is a chromosomal disorder associated with a varied combination of morphological and structural birth defects. These defects include congenital mental disability, hypotonia, characteristic body features, congenital heart defects, Hirschsprung’s diseases and others. The frequency and severity of these morphological and functional defects vary significantly among affected individuals. DS affects about one in 700 live births.

Congenital heart defect disorder or CHD is a common defect among newborn infants which can be caused by environmental or genetic factors. About 50% of babies with DS are born with CHD, which is a much higher percentage compared to the number of children without DS who are born with CHD which is approximately 1%. The most common CHD seen in infants with DS is an Atrioventricular Septal Defect (AVSD), or AV canal. Other heart defects seen in infants with DS include Ventricular Septal Defects (VSD), Atrial Septal Defects (ASD), Tetralogy of Ffallot (TOF) and Patent Ductus Arteriosus (PDA). However, the exact etiology of CHD in DS remains poorly understood. Few decades ago the frequency of CHD in DS was estimated to be approximately 20%, but now with the use of better diagnostic tool, the frequency estimated has increased to 50%. The most common CHD in the western literature is atrioventricular septal defects.