Iran J Pediatr. 2020 February; 30(1):e96734. Published online 2020 February 3. doi: 10.5812/ijp.96734. Research Article Association of Leukemia and Congenital Heart Disease in Patients with Down Syndrome Asadolah Tanasan 1 , Hossein Esfahani 2, * , Saeede Shirdel 1 and Abbas Moradi 1 1 Hamadan University of Medical Sciences, Hamadan, Iran 2 Pediatric Oncology Department, Hamadan University of Medical Sciences, Hamadan, Iran * Corresponding author: Pediatric Oncology Department, Besat Hospital, Hamadan University of Medical Sciences, Hamadan, Iran. Email: hesfehani@yahoo.com Received 2019 July 29; Revised 2019 December 07; Accepted 2019 December 20. Abstract Down syndrome (DS) or trisomy 21 is the most common type of trisomy among children. Almost half of these patients are at risk for congenital heart disease, and a minority of them may suffer from leukemia. The association of congenital heart disease and leukemia may be life threatening. It is important to determine the factors that increase leukemia in CHD. In this descriptive cross- sectional research, all patients with Down syndrome who referred to Neonatal, Pediatrics, Pediatric Cardiology, and Hematology Departments of Besat Hospital of Hamedan from 2010 to 2017 were included. Patients’ data were obtained from paper and electronic records or phone calls (if needed), and then the data was analyzed. We used odd ratio and confidence interval to study the risk increase of leukemia. Total number of patients diagnosed with Down syndrome was 118 cases. 98 (83%) cases had congenital heart disease, among them 33 cases (33.6%) had history of angiography. The most common cardiovascular diseases were AVSD (30.6%), TOF (16.3%), ASD 2 (16.3%), and VSD (15.3%), PDA (14.2%). The most common type of leukemia was ALL. Among CHD (congenital heart disease) patients, 92 (78%) cases suffered only from congenital heart disease, and 6 (5.08%) of them had leukemia and congenital heart disease simultaneously, among them 4 (66%) patients had history of angiography (P = 0.078). Two cases had leukemia without CHD. The odds ratio of leukemia in patients with DS, in association of congenital heart disease was 1.70, and in patients who had history of angiography it was 3.93 with 95% confidence interval (0.686 - 22.63) (P > 0.05). Although angiography didn’t statistically increase risk of leukemia in DS (P = 0.078), this risk increase can be clinically important. Keywords: Down Syndrome, Congenital Heart Defect (CHD), Leukemia 1. Background Down syndrome (DS) or trisomy 21 is the most com- mon type of trisomy among children (1, 2). Children with Down syndrome, in addition to the moderate mental re- tardation, are susceptible to congenital heart disease and other organ diseases that may be affected by genetic spec- trum in these patients (3, 4). Coincidence of CHD (con- genital heart defect) and other organ diseases can influ- ence prognosis and mortality rate (5, 6). Approximately half of these patients have congenital heart disease (1, 7-9) and usually require cardiac surgery, which has a good prog- nosis (10, 11), but other organ involvements (12, 13) such as leukemia may worsen the prognosis of the cardiac treat- ment (14, 15). Detection of risk factors that increase this as- sociation can be important in the management of Down syndrome (16, 17). Based on the results of some studies, ra- diation exposure may increase the risk of leukemia inci- dence (18). Down syndrome patients are prone to leukemia more than the normal population. High dose radiation that is used in the congenital heart disease angiography and intervention may increase leukemia risk in these pa- tients (19, 20). 2. Methods This descriptive-analytic study was performed on chil- dren with Down syndrome in Neonatal, Pediatrics, Pedi- atric Cardiology and Hematology Departments in the city of Hamadan between 2010 and 2017, after extracted from the paper and electronic records. Inclusion criterion was Down syndrome confirmed by karyotype and the existence of the patients’ medical records in the hospital archives. Exclusion criteria were the flawed data recorded in the pa- tients’ records and the impossibility of eliminating de- fects. After completion, the data was analyzed by SPSS- 16 software. Central and dispersion indices were used to summarize quantitative variables. To compare the risk of leukemia in children with and without congenital heart Copyright © 2020, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.