The Samaritan Fund cannot meet the needs of a group of patients with a rare disease whose medication costs up to HK$4 million a year, a Hospital Authority executive said. More than 20 patients in Hong Kong suffer from mucopolysaccharidoses, a group of inherited metabolic diseases caused by the absence or malfunctioning of certain enzymes. Cell damage affects patients' appearance, physical abilities, organs and also mental development. Most die before the age of 20. The patients and their families have been fighting to have public hospitals provide new enzyme replacement treatment, introduced two years ago. The drug costs between HK$1 million and HK$4 million a year. Beatrice Cheng Shun-yan, chief manager at the Hospital Authority, said the authority needed to consider their demands outside the Samaritan Fund because the cost was 'just too high'. 'When we talk about a medication that costs so much, the Samaritan Fund may not be a suitable mechanism to deal with this issue because just a few cases of this kind will dry up the fund,' Dr Cheng said. Ma On-tat, chairman of the Hong Kong Mucopolysaccharidoses and Rare Genetic Diseases Mutual Aid Group and father of a 16-year-old patient, said the medication was the patients' only hope. 'We don't mind which fund the government uses to pay for the drugs, as long as they give them to our patients. We cannot just wait and see our children die,' he said. 'The Samaritan Fund takes many years to add one drug to its list, and that is too long for the patients.' Mr Ma said only about 10 patients in Hong Kong were suitable for the treatment. Patients' Rights Association spokesman Tim Pang Hung-cheong said the government should set up a designated fund to help patients with very rare diseases.