The Department of Buildings, announcing its findings, called the defect so rare that its experts could not recall a similar case.

Gustine's only desire is for her baby, born with an extremely rare anatomical defect, to live to adulthood.

This rare defect may occur as part of a syndrome or as an isolated abnormality.

As many as 600 patients have been given gene therapy in studies, for diseases ranging from rare metabolic defects to common cancers.

Bartter syndrome is a rare inherited defect in the thick ascending limb of the loop of Henle.

Ms. Register's own interminable illness, a rare congenital defect of the liver known as Caroli's disease, provides the experimental and emotional ground for the book.

This has been pursued for decades and, of the rare defects found, the vast majority are associated with nonnuclear components that can be tested in the laboratory.

But Dr. Zirkin said several hundred animals was not enough to pick up a rare or subtle defect.

A fetus with a rare, severe defect sometimes dies before delivery.