TC genotyping by ARMS.

See text for full details. The uppercase letters are the amino acid abbreviations (M = methionine, T = threonine, I = isoleucine, L = leucine, Q = glutamine, R = arginine, P = proline, S = serine). The numbers represent the codons where an amino acid substitution has been identified. We detected a polymorphism in codon 259 but not in 198, 219, 234, and 376. In HT-29 cells, proline or arginine are present at 259 whereas, in Caco-2 cells, only arginine is present. A homozygous 259-P Caucasian is also shown.