In summary, the patients in the PNH group had a significantly higher prevalence of aplastic anaemia, myelodysplastic syndrome, anaemia, haemolytic anaemia, pancytopenia, thrombocytopenia, Budd-Chiari syndrome, other thromboses, embolism, haemoglobinuria, haemolysis, haematuria, abdominal pain, dysphagia, lethargy, backache, urinary tract infections, skin infections, renal dysfunction, shortness of breath, blood transfusions, bone marrow tests, hospitalisations, haptoglobin tests, blood tests and referrals to haematology, gastroenterology, and urology, as compared to the control patients. The gene discussed is HP; the disease is myelodysplastic syndrome.