�PRIMETIME: MEDICAL MYSTERIES� EXAMINES RARE AND EXTRAORDINARY MEDICAL CASES ON AUGUST 16, 2006

This week �Primetime: Medical Mysteries� continues with reports on some of the rarest cases known to medicine today. While medical science has progressed exponentially, the series takes a look at the cases that still leave scientists and doctors with unanswered questions when trying to explain the human body. �Primetime: Medical Mysteries� airs on WEDNESDAY, AUGUST 16 (10:00-11:00 p.m., ET) on the ABC Television Network.

First: DNA is typically a reliable way to prove a relationship, but 30 documented cases of a rare condition show that sometimes DNA testing is not foolproof. Jim Avila reports on two women who are told that they are not the mothers of their children � that their genetic code proves they can�t be related. The women are, medically speaking, "Chimeras", and for Lydia Fairchild of Washington authorities even suspected her of acting as a paid surrogate. In applying for welfare while between jobs, Lydia and her entire family underwent a routine test to establish biological relation. The DNA test results "proved" she wasn't her children's mom, even though her obstetrician vouched for her maternity. After several tests showed the same result, Lydia found herself in danger of losing her kids. Across the country, Karen Keegan of Boston needed a kidney transplant when baffled doctors found that neither of her sons inherited her DNA. After an extensive search, doctors finally found a match in Karen�s thyroid � a second DNA in one body. But how could a person have two different genetic codes?

Then: Juju Chang reports on a disturbing disease that turns normal muscle - the muscles of the neck and arms and chest and legs - into normal bone. At the age of two, Hayden Pfeif�s parents noticed a swelling in his head on a camping trip � then Hayden became unable to move his neck. Strange masses were forming on the toddler, and doctors were doing a biopsy when a nurse noticed that his big toes were malformed -- a symptom of a condition called FOP. With only 2500 cases known worldwide, Hayden�s doctors hadn�t heard of fibrodysplasia ossificans progressiva (FOP), where normal skeletal muscle and normal connective tissue progressively turns into bone. According to Dr. Fred Kaplan, an orthopedic surgeon on the University of Pennsylvania and the world�s leading expert on FOP, �It�s a complete and devastating metamorphosis that just shouldn�t take place.� Despite the disease resulting in limited movement in Hayden�s arms and neck, the report shows how he still lives life like the five-year-old boy he is. Chang also reports on Kaplan�s search for a cure and how the for the first time there may be hope for Hayden and others affected by FOP due to a recent breakthrough. And: If the flavor of food had a shape, or the sound of a word left a bad taste, most people would think they were dreaming but for people with Synesthesia it�s a reality. Chris Cuomo reports on a condition, where senses blend with each other in unusual ways. From a woman can see distinct colors for the musical notes she plays to a pub owner who tastes processed cheese when he gives customers their change, the report features several people whose brains �crosswire� their senses.

Also: Throughout the episode there will be clues to another real life medical mystery of �You Be the Doctor.� The interactive segment will allow viewers to assess medical clues and vote online for a diagnosis. At the end of the hour, the audience will learn if they chose the right answer.

Terence Wrong and Ann Reynolds are the senior producers of �Medical Mysteries.� Rudy Bednar is the executive producer.