Array comparative genomic hybridization as a diagnostic tool for syndromic heart defects.

OBJECTIVES: To investigate different aspects of the introduction of array comparative genomic hybridization (aCGH) in clinical practice. STUDY DESIGN: A total 150 patients with a syndromic congenital heart defect (CHD) of unknown cause were analyzed with aCGH at 1-Mb resolution. Twenty-nine of these patients, with normal results on 1Mb aCGH, underwent re-analysis with 244-K oligo-microarray. With a logistic regression model, we assessed the predictive value of patient characteristics for causal imbalance detection. On the basis of our earlier experience and the literature, we constructed an algorithm to evaluate the causality of copy number variants. RESULTS: With 1-Mb aCGH, we detected 43 structural variants not listed as clinically neutral polymorphisms, 26 of which were considered to be causal. A systematic comparison of the clinical features of these 26 patients to the remaining 124 patients revealed dysmorphism as the only feature with a significant predictive value for reaching a diagnosis with 1-Mb aCGH. With higher resolution analysis in 29 patients, 75 variants not listed as clinically neutral polymorphisms were detected, 2 of which were considered to be causal. CONCLUSIONS: Molecular karyotyping yields an etiological diagnosis in at least 18% of patients with a syndromic CHD. Higher resolution evaluation results in an increasing number of variants of unknown significance.

Safety and efficacy of clopidogrel in children with heart disease.

OBJECTIVE: To evaluate the efficiency and safety of clopidogrel treatment in children with heart disease. STUDY DESIGN: We conducted single center retrospective chart review of children with heart disease at the University Hospital, Leuven, Belgium, in whom clopidogrel was used. The indication, dosage, duration of therapy, and adverse events were examined. Clinical efficacy was defined by an absence of thrombotic events. RESULTS: 46 children were identified. The mean age of first clopidogrel dose was 4.9 +/- 4.1 years. The study dosage ranged from 0.1 to 0.7 mg/kg/day clopidogrel. Almost all patients received concomitant aspirin therapy. No thrombotic events developed. Skin bruising developed in almost every patient, suggesting that clopidogrel has an anti-platelet effect. 2 patients who were treated with concomitant warfarin had bleeding complications (severe epistaxis and gastrointestinal bleeding). Hematological abnormalities were documented in 1 patient who received clopidogrel for 1 year; they reversed with medication cessation. CONCLUSION: Clopidogrel therapy in a pediatric population appears to be relatively safe and effective; however, randomized, controlled prospective studies are needed to determine the true efficacy and safety of clopidogrel in children.