DiGeorge syndrome (Chromosome 22q11.2 deletion syndrome): A historical perspective with review of 66 patients

Abstract

Aim: Congenital heart defects (CHD) are the most common major birth defects in humans. Conotruncal cardiac defects (CCD) and aortic arch anomalies, the outflow tract anomalies of the heart, usually accompany dysmorphic syndromes. Di George Syndrome, deletion of 22q11.2, is one of the typical examples for this entity. Our study was designed to determine the frequency of 22q11.2 deletion in a retrospectively ascertained sample of patients with conotruncal cardiac defects and structural cardiac defects accompanying other clinical findings of 22q11.2 deletion syndrome.Methods: A total of 66 patients (4 days-16.6 years; mean 38 months), 56 followed with the diagnosis of conotruncal cardiac defects and 10 having congenital cardiac defects other than conotruncal abnormalities participated to our study . All patients underwent karyotype and Fluorescence in Situ Hybridization (FISH) analysis for 22q11.2 deletion. After the detection of the deletion a follow up protocol was formed for the patientsResults: Five of all patients were found to have the deletion positive (7.6%). Four of them had conotruncal cardiac defects. All patients having 22q11.2 deletion had at least one abnormality of the syndrome other than cardiac problems. Facial dysmorphism and growth retardation were the most common features .Cognitive disability, feeding problems, hypocalcemia, psychiatric problems, immunity differences were the other associated problems. Parental evaluation yielded one mother to be a deletion carrier.Conclusion: We suggest that 22q11.2 deletion must be explored in all newborns with selective conotruncal cardiac defects and with non- conotruncal cardiac defects accompanying the other anomalies of the syndrome. All deletion positive patients must be evaluated for the accompanying features of the syndrome with genetic counselling.