Frequency and Clinical Characterization of Patients with Immune Thrombocytopenic Purpura Cytogenetically Tested for 22q11.2 Deletion Syndrome

Thrombocytopenia occurs in peripheral blood when the destruction, utilization or sequestration of platelets exceeds medullary ability to produce platelets. Among the causes of thrombocytopenia is ITP (immune thrombocytopenic purpura), which is a condition that was characterized by the formation of autoantibodies against the human platelet antigen system. ITP is considered to be one of the findings described within the broad clinical spectrum of 22q11.2 deletion syndrome (SD22q11.2). Also known as velocardiofacial syndrome or DiGeorge syndrome, SD22q11.2 is an autosomal dominant condition with variable expressiveness, which is caused by a deletion that involves the 11.2 region of the long arm (q) of chromosome 22. Our objective was to evaluate the frequency and clinical characteristics of individuals with SD22q11.2 among patients diagnosed with ITP. A total of 38 patients were analyzed through the application of a standard protocol with collection of clinical and epidemiological data, and the application of the FISH (fluorescent in situ hybridization) technique to study 22q11.2 micro-deletion. No cases of SD22q11 were identified in the sample using the FISH technique.