Apolipoprotein E and transferrin genotyping by ligation detection reaction and universal array

Genetic studies in Alzheimer disease (AD) have indicated that its etiology is multifactorial. The apolipoprotein E locus (APOE) is a known major susceptibility factor, and additional genetic loci have been associated with disease development. Among many others, the transferrin gene (TF) has been suggested as a candidate locus for AD because it is the major transport protein for iron, which itself is an important factor in free-radical generation. Oxidative stress and free-radical damage occur in AD, which justifies the interest in this protein. Previous studies have shown contrasting results regarding the influence of combinations of TF and APOE alleles. We therefore designed a large-scale study of AD patients and controls to ascertain the relevance of TF as a risk factor for AD in conjunction with APOE. Here, we present the method that we have established for the simultaneous typing of the APOE and TF genes based on the ligation detection reaction (LDR)/universal array approach proposed by Gerry et al.