Patrick Doherty had always been very active. He trekked the Himalayas and hiked trails in Spain. But about a year and a half ago, he noticed pins and needles in his fingers and toes. His feet got cold. And then he started getting out of breath any time he walked his dog up the hills of County Donegal in Ireland where he lives. "I noticed on some of the larger hill climbs I was getting a bit breathless," says Doherty, 65. "So I realized something was wrong."
Doherty found out he had a rare, but devastating inherited disease - known as transthyretin amyloidosis - that had killed his father. A misshapen protein was building up in his body, destroying important tissues, such as nerves in his hands and feet and his heart.