A group that represents Canadians with rare disorders is calling for a national policy to help pay for their astronomical medical costs.

The call comes after the Alberta government decided to pay for a drug for a 17-year-old boy stricken with Pompe disease, a rare and potentially fatal disease caused by an enzyme deficiency that disables muscles.

Trevor Pare of Innisfail has been a participant in a clinical trial that paid for the drug Myozyme. The trial is over at the end of May and the Alberta government has decided to take over the annual cost, which is more than $500,000.

"It's just like unbelievable, unbelievable," Linda Pare, Trevor's mother, told CBC News. She said without the drug, her son would die in six months.

The Canadian Organization for Rare Disorders is pleased Trevor will continue to get his special drug.

But Durhane Wong-Rieger, president of the organization, said it is time for a national policy on funding of drugs used to treat rare diseases.

"You've got families like Trevor's who have to go to the media and go begging to the government to get help and the sad news is even if we get one [paid for], we have to start all over with another," says Wong-Rieger. "Sometimes we even get a whole disease covered; then when the next disease comes along, we're starting all over again.

She said Canada is one of the few developed countries in the world that does not have a policy for rare disorders.

Alberta Health Minister Ron Liepert said the province is working on a policy to deal with all Albertans who require very expensive drugs for rare disorders. But because the policy hasn't been hammered out, the government decided to step in and pay for treatment in Pare's case.

"We're not yet ready with the policy — it will be part of the pharmaceutical strategy that we roll out over the next few months," says Liepert. "However, in this particular case his clinical trial was expiring and caucus made a decision and it is a moral decision and we will be funding the drug through the Blue Cross plan."