“…Genomic DNA was isolated from peripheral blood by the salt extraction method. Polymerase chain reactions for three DNA fragments were performed as described (12,13). Restriction fragment length polymorphism analyses with HpaII, Tsp509I, AvaII, and SacI restriction enzymes were used to detect the Q188R, K285N, and N314D mutations and the IVS5-24GϾA intron variation, respectively (12,13).…”