The parents of control subject P, who has the uncommon ΔGT/GTGT ratio of 1:2, both have a ratio of 1:1, suggesting that they carry one copy of each of the extended haplotypes.

Exon 2 of NCF-1/ψNCF-1 in genomic DNA of the parents and siblings of control subject P (indicated by an asterisk in the pedigree) was amplified, and the ratio of ΔGT to GTGT sequence was estimated using the sequence- and gel-based methods. Both parents were found to have a ratio of 1:1, which is consistent with our hypothesis that subject P is homozygous for the extended haplotype that contains a single copy each of the Type I and Type II pseudogenes. The siblings both had ΔGT/GTGT ratios of 1:1. The family is unaffected by CGD. All other details are the same as in Figure 5.