Genetic classification of chronic granulomatous disease.
| Component Affected . | Gene Locus . | Subtype* . | Flavocytocrome b558 Spectrum . | NBT Score (% Positive) . | Frequency (% of Cases) . |
|---|---|---|---|---|---|
| gp91phox | Xp21.1 | X91 | 0 | 0 | 56 |
| X91- | Low | 80-100 (weak) | 5 | ||
| X91- | Low | 5-10% | 2 | ||
| X91+ | N | 0 | 2 | ||
| p22phox | 16q24 | A220 | 0 | 0 | 6 |
| A22+ | N | 0 | 1 | ||
| p47phox | 7q11.23 | A470 | N | 0 | 23 |
| p67phox | 1q25 | A670 | N | 0 | 6 |
| Component Affected . | Gene Locus . | Subtype* . | Flavocytocrome b558 Spectrum . | NBT Score (% Positive) . | Frequency (% of Cases) . |
|---|---|---|---|---|---|
| gp91phox | Xp21.1 | X91 | 0 | 0 | 56 |
| X91- | Low | 80-100 (weak) | 5 | ||
| X91- | Low | 5-10% | 2 | ||
| X91+ | N | 0 | 2 | ||
| p22phox | 16q24 | A220 | 0 | 0 | 6 |
| A22+ | N | 0 | 1 | ||
| p47phox | 7q11.23 | A470 | N | 0 | 23 |
| p67phox | 1q25 | A670 | N | 0 | 6 |
In this nomenclature, the first letter represents the mode of inheritance (X-linked [X] or autosomal recessive [A]). The number indicates the phox component that is genetically affected. The superscript symbols indicate whether the protein expression of the affected component is undetectable (0), diminished (-), or normal (+). X91+ and A22+ represent crossreactive but defective enzymes. Abbreviations: N, normal; NBT, nitroblue tetrazolium test. Frequency of cases represents data from 121 families.65,66