Inherited t(9;22) as the cause of DiGeorge syndrome: a case report.

DiGeorge syndrome is associated with microdeletion of chromosome 22q11.2. Most cases occur sporadically although vertical transmission has been documented. We report a rare case of DiGeorge syndrome in an 8-year-old girl. Blood sample of the patient was cultured and harvested following standard procedure. All of the 20 cells analysed showed a karyotype of 45, XX, -22, t (9;22) (p23; q11.2). Cytogenetic investigation done on the patient's mother revealed that she was the carrier for the translocation. Her karyotype was 46, XX, t (9;22) (p23; q11.2). Fluorescence in situ hybridisation (FISH) analysis using TUPLE1 and N25 (Vysis, USA) probes showed deletion of the 22q11.2 region in the patient, confirming the diagnosis of DiGeorge syndrome. FISH analysis showed no deletion of the region in the mother.