The most likely source of the infections appears to be another person with an initially undiagnosed case at North York Hospital, officials said.

About 4,600 people in North America are known to have the condition, the Williams Syndrome Association said, though there may be 10,000 undiagnosed cases.

However, a coroner's inquest in April 2009 determined that Perkins had suffered from an undiagnosed case of channelopathies, which caused his heart to stop suddenly.

He suffered from an undiagnosed case of dyslexia which made him an outsider among the other children in the neighborhood.

Since efforts to track the disease are just starting, they say there are probably far more undiagnosed cases.

Lieberman had checked San Jose Mercy's databases for similar undiagnosed cases reported within the last forty-eight hours and found none.

She's written several on the topic, having had an undiagnosed case of the autoimmune disease for years.

He struggled academically, suffering from an undiagnosed case of dyslexia.

Academically, Fielding suffered setbacks through an undiagnosed case of dyslexia, and this led to problems studying subjects such as English.

One mile out: Four epileptics suffered grand-mal seizures, including one previously undiagnosed case.