How does this make you feel?

http://www.canadiancrc.com/Newspaper_Art...DEC02.aspx

They came to the hospital together, a husband, a wife and the little daughter they feared had been cursed by inheritance. Since birth, she had struggled to breathe, and all the signs pointed to cystic fibrosis.

If the girl truly had the incurable disease that clogs the lungs, she had to have received two copies of a CF gene, one from each parent. Tests at the Hospital for Sick Children in Toronto confirmed the family's worst fears -- and then some.

The girl was indeed afflicted. Her mom carried one of the culprit genes. But her dad, the doctors discovered, was quite a different story. His DNA showed no sign of a CF gene, which means he is not a carrier and he is not her dad.

Hospital staff have felt bound to keep the secret from him. But when they told the mom, it came as no surprise; it rarely does.

In the early 1970s, a schoolteacher in southern England assigned a class science project in which his students were to find out the blood types of their parents. The students were then to use this information to deduce their own blood types (because a gene from each parent determines your blood type, in most instances only a certain number of combinations are possible). Instead, 30 per cent of the students discovered their dads were not their biologically fathers.

In one family with four daughters, the DNA analysis was so surprising that counsellors asked the mother to explain. "It turned out that the daughters had three different fathers," said Peter Ray, a scientist at the hospital.