Trial Information

Evaluation of Thiopurine Methyltransferase Polymorphisms in the Hispanic Population

Relatively few studies have been performed evaluating the variant allele frequencies in
Spanish populations. To date, no studies evaluating the TPMT variant allele frequency in the
Hispanic population have been reported. Hispanics are a growing part of the patient
population treated in the United States. Characterization of the proportion of patients with
variant genotypes in this population is important since Hispanic children represent a
significant proportion of children being treated with thiopurines.

A single 3 cc heparinized blood sample will be obtained for TPMT genotyping. The sample will
be obtained either simultaneously with a clinical sample, at the time of an otherwise
medically indicated intravenous catheter placement or scavenged from excess blood remaining
following clinical laboratory testing.