22q11.2 deletion syndrome and complex congenital heart defects

OBJECTIVE: Investigate the frequency of 22q11 deletion syndrome among patients with complex congenital heart disease. METHODS: A prospective and consecutive cohort of patients with complex heart defects was evaluated in their first hospitalization at a cardiac intensive care unit of a pediatric hospital. For each patient a protocol of demographic and clinical evaluation was filled. High resolution karyotype and 22q11 microdeletion by fluorescence in situ hybridization was investigated. The heart defects were classified by a cardiologist of the study. RESULTS: The cohort comprised 66 patients. Karyotypic anomalies were observed in 5 patients (7.6%), however none of those was the 22q11 deletion. Evaluation by means of FISH was successful in 65 patients and 22q11 microdeletion was identified in 2 (3.1%). Of the 66 patients with complex defects, 52 were carriers of conotruncal malformations and in 51 the 22q11 microdeletion analysis by FISH was successful. Both 22q11 microdeletion carriers belonged to this group, representing a frequency of 3.9%. They presented tetralogy of Fallot. CONCLUSION: 22q11DS is a frequent abnormality among patients with complex and conotruncal heart defects. Variations of the 22q11DS frequency among studies seem to be mainly associated to criteria for patient selection and specific characteristics of the population in analysis.

DiGeorge syndrome; in situ hybridization; fluorescence; heart defects; congenital; chromosomes, human, pair 22

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