An anonymous donor has stepped up to buy a home for a single mother in Airdrie whose daughters have a rare disease that will leave them both in wheelchairs.

Earlier this year, Shanna Leavitt learned both her daughters Kadence, 11, and Addison, 9, have Friedreich's ataxia — a rare genetic neurological disease that leads to slow deterioration of the muscles and can affect the eyes and heart.

The illness has no cure.

"I don't know how to thank people enough," said Leavitt when she was told about the anonymous donor earlier this month, surrounded by her three sisters and close friends.

Emotional surprise

Shanna Leavitt

Shanna Leavitt tears up after she finds out about the donation. (YouTube screengrab)

"It's amazing how generous and how big people's hearts are," she said as tears rolled down her cheeks.

The Leavitts take possession of their bungalow in April, but still need to raise money to make the home wheelchair accessible.

The "incredibly generous" angel investor purchased the home, and will pay the mortgage until such time as Leavitt can afford to take on the payments herself, said volunteer organizer Bridget Brown.

The family is applying for grants and looking for tradespeople to donate their services.

Kadence Addison and mom Shanna Leavitt

Mom Shanna Leavitt says Addison, left, will soon need a walker to get around. (