A trial is underway in Winnipeg for what could be a life-saving cure for a rare genetic disease.

Montreal-based drug company Enobia Pharma has brought parents from all over the world to Winnipeg. Their children have hypophosphatasia – a bone disease.

Nicole and Matt Siemens' son Gideon has the disease. He has no skull and his bones are missing or extremely thin. Like most babies diagnosed with hypophosphatasia, he was not expected to live more than a few weeks.

"We didn't know what was wrong at first because he looked like he does right now," said Nicole Siemens.

Dr. Cheryl Rockman-Greenberg is conducting the testing of a drug known as enb-0040 at the Health Sciences Centre. She has been studying hypophosphatasia since the 1980s.

The drug helps the body use minerals like calcium and phosphate so they can grow stronger.

Baby Amy was the first child to take part in the trial, in 2008. Her parents brought her to Winnipeg from Ireland. Now, she's living a normal life.

Dr. Rockman-Greenberg said that other families also have reason to be optimistic. The disease is particularly common among Manitoba Mennonites, so province might have the most to gain from a breakthrough.

"There's nothing that I see that leads me to believe that we should be anything but totally optimistic that we turn a previously untreatable disease into a treatable disease," she said.

So far, 33 patients have taken part in the testing. Older children, with less-severe cases who were diagnosed later in life, are also taking part.

- with a report from CTV's Nancy Carlson