1.   By sequencing, or closely mapping, the structure of the gene, the scientists found that all people with the disease carried defective versions of it.

2.   Most common maladies, like heart disease and schizophrenia, are thought to be caused by the defective versions of many genes acting in concert.

3.   These are the genes that almost surely cause illness in people born with defective versions of them.

4.   But the mice in the experiment had a defective version of the gene.

5.   Jeffrey Trent of the genome research institute, senior author of the paper, said defective versions of the gene might also make prostate cancer more aggressive.

6.   Researchers found that a defective version of the gene was inherited along with retardation in a large family.

7.   They know the gene makes brain cells produce a defective version of a normal protein.