No abstract

Background: Down syndrome (DS) is the most common chromosomal abnormality in newborns and is associated with other congenital malformations and health problems. The features of Down syndrome differ according to ethnicity and geographic region. Objectives: The main aim was to assess the clinical characteristics of DS patients in a referral pediatric cardiology department. Patients and Methods:In this cross-sectional study, we assessed the clinical characteristics of children with Down syndrome and heart defects in an educational hospital over 11 years (from September 2001 to September 2012) in Iran. All data were collected according to a checklist created by the researchers, which included the clinical information, genetic characteristics, cardiac and non-cardiac co-existing diseases, and parental variables of the children. An independent t-test and a chi-square test were used to compare qualitative variables such as birth weight and age of diagnosis. P < 0.05 was considered statistically significant. Results: 100 patients with Down syndrome and congenital heart disease were evaluated; 52 were female (52%) and 48 were male (48%). The average birth weight of the subjects was 2745 ± 523 (mean ± SD) grams. The mean age of the patients' mothers was 32 ± 6 years, and the mean age of the patients' fathers was 36 ± 6 years. Chromosomal analysis was performed for 61 patients, 60 of whom had free trisomy (98.4%), one of whom had translocation (1.6%), and none of whom had a mosaic pattern of chromosomal abnormality. The parents of 33 the patients in this study were consanguineous. All patients had cardiac disorders, but non-cardiac disorder also was recorded in 37 patients (37%). The most common non-cardiac disorder in patients was hypothyroidism, and the second most common was gastrointestinal problems. Conclusions: Parents were blood relatives in 33 (33%) of the patient cases, which is a very high rate. Therefore, non-random mating is an important issue in developing countries that needs more attention