Clinicopathologic features of the 2 congenital porphyrias most relevant to the hematology consultant
| . | AIP . | EPP and XLP . |
|---|---|---|
| Affected gene | HMBS | FECH (EPP) |
| ALAS2 (XLP; 2%–10% cases) | ||
| CLPX (1 case) | ||
| Prevalence of disease-causing mutation* | 1/2000 | FECH c.315-48T>C in 31%–43% (Southeast Asia and Japan), 10% (Europe), <3% (Africa) |
| Prevalence of symptomatic disease* | 0.5–10/100,000 | 0.5–2.7/100,000 |
| Tissue origin | Liver | Erythroid precursors |
| Pathologic porphyrin precursors | ALA | Protoporphyrins |
| PBG |
| . | AIP . | EPP and XLP . |
|---|---|---|
| Affected gene | HMBS | FECH (EPP) |
| ALAS2 (XLP; 2%–10% cases) | ||
| CLPX (1 case) | ||
| Prevalence of disease-causing mutation* | 1/2000 | FECH c.315-48T>C in 31%–43% (Southeast Asia and Japan), 10% (Europe), <3% (Africa) |
| Prevalence of symptomatic disease* | 0.5–10/100,000 | 0.5–2.7/100,000 |
| Tissue origin | Liver | Erythroid precursors |
| Pathologic porphyrin precursors | ALA | Protoporphyrins |
| PBG |
Western Europeans and European Americans.1