The common structural variants of C6 have been used to study the linkage relations of the locus in human pedigrees. Linkage between C6 and RH, Fy, ACP1, MNSS, Jk, HLA, ABO, ESD, Hp, ADA, GPT, Gc, Pi, Gm and Km has been excluded at recombination fractions at least as great as 0-1 in the male.