HEMOPHILIA

Although the nature of haemophilia has been understood for thousands o f years, knowledge of its molecular genetics is recent. These X-linked bleeding disorders have diverse underlying DNA defects and, in 1992, DNA inversion within the X chromosome was found to explain half of the most serious cases of haemophilia A. The life-span and quality-of-lif e for patients with haemophilia had improved steadily throughout the e arly 1980s but the principal cause of death remained intracranial haem orrhage until the epidemic of HN infection due to contaminated factor concentrates. Infection with hepatitis C virus is almost universal for patients treated with clotting factors before 1985. No curative treat ment is available for hepatitis C at present. Knowledge of the transmi ssion of viruses in concentrates has led to important developments in processing techniques to eliminate them. Recombinant technology has pr oduced factor VIII and, more recently, factor TX concentrate which is likely to be very safe. Development of inhibitors to factor concentrat es (especially factor VIII) remains one of the most serious complicati ons of haemophilia. The variety of treatments available testifies to t he lack of a single universally efficacious one. The use of prophylact ic treatment has been conclusively demonstrated to result in a preserv ation of joint function in severely affected patients who might otherw ise develop significant joint problems. The many facets of the care of patients with severe haemophilia, ranging from dental care to genetic counselling, can be advantageously co-ordinated in a haemophilia comp rehensive care centre.