TORONTO -- A Kingston, Ont., man is set to donate part of his liver to save one of his twin girls, but cannot donate to both.

Michael and Johanne Wagner's three-year-old twin girls have Alagille syndrome which affects the function of their livers.

Doctors say both need transplants to survive, but the girls' mother says their father is the only match that has been found so far.

Johanne Wagner says surgeons at Toronto General Hospital are set to operate on Michael and one daughter in about two weeks.

They cannot bear to choose, so doctors will decide based on the best candidate.

The couple is waiting to find a donor for their other daughter, who will die without a new liver.