Molecular Cytogenetics Findings in Patients with Clinical Suspicion of 22q11.2 Deletion Syndrome

Congenital heart defects are changes in the development of the heart and large vessels. Their exact etiology is unknown, however, they have an association with genetic diseases, such as 22q11.2 deletion syndrome, which is caused by a 22q11.2 deletion. Thus, we report four patients diagnosed with congenital heart disease whose cases are suggestive of 22q11.2 deletion syndrome. Case 1, diagnosed with interatrial communication, pulmonary atresia and restricted intrauterine growth; Case 2, diagnosed with pulmonary atresia, complete atrioventricular septal defect, right isomerism, hypoplastic left heart syndrome and anomalous pulmonary venous drainage; Case 3, diagnosed with transposition of the large arteries; Case 4, diagnosed with interventricular communication, cervical vertebra fusion, left lung hypoplasia and ribcage deformity. The results of the karyotyping were as follows: cases 1 and 2 - 46, XY; case 3 - 46, XX; and case 4 - 47, XY, + 21. The FISH revealed an absence of deletion in the N25 and N85A3 regions. Of the four patients with congenital heart disease suggestive of 22q11.2 deletion syndrome, only one presented chromosomal anomaly, the free trisomy of chromosome 21. Although we have a negative result for FISH (fluorescence in situ hybridization), this does not eliminate the possibility of the presence of deletion in the 22q11.2 region, since patients may present deletions in cregions. Thus, cytogenetic/cytogenomic analysis was essential for the etiological elucidation of patients with congenital heart disease, even if they presented negative results for FISH. Cytogenomic analyses are necessary to elucidate whether there is deletion in the 22q11.2 region in these reported patients.