Red Cross workers began preparations yesterday to launch a bone marrow campaign to save a 10-year-old boy dying from a rare blood cell disease. Leung Ka-fai was born with a hereditary illness called chronic granulomatous disease and has been in and out of hospitals since he was three. Two of his older brothers died from the disease. A two-year drive by Queen Mary Hospital for potential donors with the right bone marrow type from databases in the United States, Britain, Japan and Hong Kong has proved fruitless. The disease prevents the production of a crucial enzyme, which renders the white blood cells unable to fight germs. 'Two of my sons have died of the disease. I don't want to lose my last son,' said Ka-fai's mother, Leung Yin-mei. University of Hong Kong paediatrician Dr Lee Tsz-leung, who is treating the boy, said Ka-fai had been among the sickest of patients suffering from the disease that he had seen. A campaign to publicise Ka-fai's plight and that of other patients on a bone marrow waiting list will be launched on Saturday and Sunday at Tsuen Wan's Discovery Park Shopping Centre. Three Red Cross stations in Central, Yau Ma Tei and Tsuen Wan will also start testing for potential donors from next Monday until the end of the month. Queen Mary Hospital has 12 such patients. Campaign organisers Apple Daily and the Hong Kong Marrow Match Foundation can be contacted on 2990-8688 and 2855-9855 respectively.