1.   A body clock that confuses day and night causes some symptoms of a rare genetic defect, scientists say.

2.   In colon cancer, familial adenomatous polyposis is very strongly associated with the FAP gene, but it is a rare defect.

3.   A hormone produced in fat cells can be used to help people lose weight, according to a study of an obese child with a rare genetic defect.

4.   Bone marrow transplants traditionally are performed to fight cancer or to correct rare genetic defects.

5.   The last of four brothers born with a rare genetic defect that left them appearing to be female underwent surgery Sunday to fully become a boy.

6.   The last of four siblings born with a rare defect that left them appearing female but genetically male underwent surgery Sunday to become a boy.