Identification of A470 CGD patients who were not homozygous for the common ΔGT mutation.
Genomic DNA from a nonaffected donor, a classic (ΔGT/ΔGT) A470 CGD patient and carrier parent, and patients 2 and 5 was amplified using primers 2LB2 and 2RB2, which do not differentiate between NCF-1 and ψNCF-1. Electropherograms show the first 10 nucleotides of exon 2. In the nonaffected person (A), co-amplification of functional gene and pseudogene DNA was evident because the sequences diverged after the initial GT. In contrast, the ΔGT/ΔGT A470 CGD patient showed only pseudogene sequence (E). The obligate heterozygous carrier of this common form of the disease exhibited both NCF-1 and ψNCF-1sequence (C) but with a much higher pseudogene–functional gene ratio than seen in normal DNA. Patients 1 to 4 (only patient 2 is shown; D) had electropherograms similar to those of the carrier, indicating they were heterozygous for the ΔGT mutation. Patients 5 and 6 (only patient 5 is shown; B) were similar to the normal control, suggesting their p47-phox deficiency was not associated with a GT deletion in NCF-1.
