Inhibitors present in blood do not inhibit PCR from buccal cell preparations: Case report

Background: Hemochromatosis is a common disease that is characterized by high ferritin levels and/or high iron saturation and mutations in two alleles. Material and Methods. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) is often performed on DNA extracted from blood since blood yields high concentrations of DNA. However, inhibitors can cause PCR failure in DNA extracted from blood thus preventing a molecular diagnosis. Results. This report describes a case where multiple blood draws resulted in unamplifiable DNA. Subsequently, a buccal cell sample was collected and extracted. DNA extracted from the buccal cells yielded amplifiable DNA in contrast to DNA extracted from the patient's blood. In addition, the patient was identified as having a homozygous mutation for one allele of the hemochromatosis gene. Conclusion. These results suggests that a buccal cell DNA extraction may be useful in cases where blood samples contain inhibitory substances for PCR.