RDT: rapid diagnostic test; IgM: immunoglobulin M; LDH: lactate dehydrogenase; TIBC: total iron binding capacity; TSH: thyroid-stimulating hormone; T3: triiodothyronine; PT: prothrombin; RA factor: rheumatoid factor; ANA by IFA: antinuclear antibody by immunofluorescence; ACE: angiotensin-converting enzyme; IL: interleukin; CPK: creatine phosphokinase; MPO: myeloperoxidase; ANCA: anti-neutrophil cytoplasmic antibodies; PR3: proteinase 3; PNH: paroxysmal nocturnal hemoglobinuria. The gene discussed is MPO; the disease is paroxysmal nocturnal hemoglobinuria.