Fig. 2.

Pedigree of family members tested for the multibase deletion in their ABO gene. The ABO phenotypes as determined by serologic testing are listed, the members typed positive for the genetic alteration are indicated in bold print. Sixteen individuals, spanning three generations (II, III, IV), were found to have shared the deletion in their ABO gene. The mutation, when present in trans with a common ABO*O or B allele was reflected in the absence of A antigen expression in the affected family members (1, 2, 3, 5, 18, 20, 21, 22, and 29). n.a. = not available.