very long, but worth the read...Parkinson's and Alzheimer's are mentioned. >Mitochondria supply the body with energy, but they also may carry >genetic diseases by Faye Flam, Knight-Ridder Newspapers (KRT) >PHILADELPHIA - In retrospect, Janine Swift had never been quite healthy. >She didn't have much energy, rarely running or playing outdoors with other >children, said her mother, Theresa, 41, of Collingswood, N.J. >"As a little girl, her hands sometimes used to tremble," her mother said, >but doctors could offer no explanation. "We thought maybe she was just a >nervous kid." >There was nothing to warn of the latent disease that would suddenly attack >her nervous system in March 1995, when Janine turned 16, a disease >surprisingly common - yet unknown to many doctors - that is pushing >scientists to the limits of microbiology. >First, Janine told her mother she had a headache, saw colored lights, and >felt nauseated - classic symptoms of migraine headache. "The next day she >was on the bathroom floor, having a seizure," said Swift. >Over the next two years, the teen-ager's vision deteriorated. She became >too weak to walk. The seizures, some lasting hours, kept coming, >hospitalizing her for months. No one could figure out what was wrong. >"We had EEGs, MRIs, spinal taps. ... We put her through all the tests," her >mother said. >Then, while taking a family history, a doctor at St. Christopher's Hospital >for Children found that Theresa Swift herself had suffered some unexplained >symptoms, starting a decade earlier, at age 30. Doctors thought it might be >multiple sclerosis. At 35, she says, something happened to her vision >-colors faded to white and stayed that way for weeks. First it happened in >her right eye, then her left. >Tests confirmed that Swift carried an abnormal gene that she had passed not >only to her sick daughter but to two of her other three children as well. >The gene causes a disorder Swift had never heard of - mitochondrial >disease. >In the teen-age daughter, the disease was wreaking havoc deep inside the >cells of her body, destroying the microscopic structures called the >mitochondria that normally combine molecules of food with oxygen, providing >the body with energy. >The same thing has been happening to the mother, only more slowly. >Mitochondrial diseases affect 1,000 to 4,000 American children born each >year, according to the Mitochondrial and Metabolic Disease Center at the >University of California, San Diego. Most of the children die before >adolescence. >So far, dozens of different mitochondrial disorders have been identified, >many with cumbersome names such as mitochondrial encephalomyopathy with >lactic acidosis and stroke-like episodes, reflecting the baffling array of >symptoms they produce - fatigue, headaches, seizures, strokes, diabetes, >learning disabilities, slow growth, blindness and deafness. >Doctors are still struggling to understand how mitochondrial disease works. >They cannot offer a cure. >"There's a feeling of helplessness because we're dealing with the unknown," >said Sharon Ditchey, a dietitian with two children who have been affected, >one of whom died. Melissa, now 5, suffers from migraine headaches, >arthritis, and deafness. >As with other genetic defects, the problem is often inherited, but it can >also happen spontaneously. >The disease can come swiftly, as it does in some children. Or it can emerge >gradually - in some cases, perhaps not until old age. >New research shows that mitochondrial problems underlie Alzheimer's and >Parkinson's diseases, as well as some cases of heart disease and >adult-onset diabetes. >And even in children, such as Janine Swift, mitochondrial disease often >goes unnoticed until it reaches a critical point at which the deterioration >of the mitochondria causes a breakdown of muscles or organs, including the >brain and central nervous system. >"It took one thing after another from her," said her mother. Two weeks ago, >at age 18, she died. >Though the first case of a mitochondrial disease was diagnosed in 1962, it >was not until the mid-1980s that doctors began to recognize more cases in >children. Experts now suspect that many patients are wrongly diagnosed as >having cerebral palsy, epilepsy, multiple sclerosis, or "failure to >thrive." It may even account for instances of sudden infant death syndrome. >"We need to convince doctors these disorders are common and important," >said Douglas Wallace, an Emory University biologist who attended an >international meeting on mitochondrial diseases last month in Philadelphia. >"Until recently, it was considered stupid to look at the mitochondria" as a >cause of disease, says Wallace. The changing attitude took a revolution in >scientists' understanding of these tiny cellular power plants. >High school textbooks have long depicted the mitochondrion as a folded >ribbon surrounded by an oval-shaped membrane. The snapshot was accurate but >the standard definition - an organelle, or tiny organ, with the job of >making energy - didn't capture its strangely independent nature. >In 1963 scientists discovered that the mitochondria carried their own set >of genes, made from their own DNA. (Before that, scientists thought all >human DNA was contained in the 23 pairs of chromosomes inside the cell's >nucleus.) >The genes in the mitochondria pass only from mother to offspring - egg >cells carry mitochondria, while sperm cells do not. >Stranger still, some scientists have come to see the mitochondria not as a >standard part of our bodies but as a life form in itself - a benevolent >parasite. >The way Wallace explains it, about a billion and a half years ago, a >slender, thread-like bacterium slithered inside a larger one-celled >organism. >Both life forms benefited from the invasion. The bacterium gained the >protection and mobility of its much larger host, and the host benefited by >absorbing some of the energy that the invader pumped out. The invader used >an efficient, oxygen-burning process that the host cell had not evolved. >This mutually beneficial - or symbiotic - partnership worked so well that >the two evolved together into fungi, plants and animals. >The discovery of the mitochondria's own set of genes backed this scenario >of an independent origin, especially after analysis showed that the >mitochondria's closest relative is a free-living bacteria. >The late Carl Sagan noted the implications of this concept in Broca's >Brain: "We are not single organisms but an array of about 10 trillion >beings, and not all of the same kind." >Emory's Wallace takes such thinking a step further, arguing that, as >composite beings, we can die one of two ways - either the body's cells die, >or the mitochondria within them die. >He suspects that everyone's mitochondria are programmed to give out at some >point, usually in old age. In other words: "Mitochondrial diseases might >be the most common cause of death." >According to Wallace's view, aging is just a slower version of childhood >mitochondrial disease. First, the deteriorating mitochondria may make an >aging person feel tired, but once the damage passes a critical threshold, >various organs give out. If the damage first affects the brain, it may show >up as Alzheimer's or Parkinson's diseases. >Some drugs that are aimed at killing viruses also poison the mitochondria, >says Robert Naviaux of the University of California, San Diego. >Some cases of mitochondrial disease come from drugs aimed at attacking >viruses. One example, says Naviaux, is the AIDS drug AZT, whose side >effects, he says, come from its attack on mitochondria. And about five >years ago, an experimental hepatitis B drug, fialuridine, unexpectedly >killed 5 people in a drug trial. Their mitochondria had been irreparably >damaged. >At the Philadelphia meeting, about 170 researchers and 200 parents focused >on the childhood diseases. >The most notable area of progress: The finding that certain restrictive >diets and vitamin supplements can relieve symptoms in some children. >That knowledge has been some help for another mother at the conference, >Eileen Murphy of San Diego. Murphy says she and her husband struggled to >get their baby to drink more than a few drops of formula at a time. >Doctors told Murphy it was just first-time-parent anxiety. Her baby, >Cristin, didn't look wasted. "She had these chubby little cheeks," said >Murphy, but the child seemed listless. >By her 13th month, Cristin hadn't made progress toward walking or talking. >Doctors thought she had cerebral palsy - a diagnosis usually foreshadowing >a life of physical and mental disability. >"I was devastated," said Murphy, who started to search for other diagnoses, >combing medical literature, surfing the Internet, and crisscrossing the >country to meet doctor after doctor. >Eventually, a gastroenterologist made the diagnosis. >"When I realized she was dying," said Murphy, "then I wished it could have >been just cerebral palsy." >In Cristin's case, the problem was an inability to break down fats. Instead >of working toward energy and growth, molecules of fat were lodging in her >muscles, explaining her floppy limbs and chubby cheeks. >Murphy says that after fat was cut from Cristin's diet, the girl - now 3 - >has gained weight and started walking. Still, Cristin's doctors don't >expect her to survive to adolescence. >In an effort to help her daughter, Murphy quit her job as an engineer for >Hewlett-Packard, studied microbiology, and now works with the mitochondrial >research group in San Diego. >Wilmington, Del., couple Marsha and Allen Barnett have also made it their >mission to raise public awareness and to increase research funding. In the >early 1980s, the couple lost two of their three sons to a mitochondrial >disorder called Leigh's disease. Michael was 10 and Charles was 6. >The couple started the Michael and Charles Barnett Memorial Fund, raising >money for a mitochondrial research center at St. Christopher's. >For more information on mitochondrial disorders, call United Mitochondrial >Disease Foundation, Monroeville, Pa. 412-856-1297. >(c) 1997, The Philadelphia Inquirer. >Visit Philadelphia Online, the Inquirer's World Wide Web site, at >http://www.phillynews.com/ >Distributed by Knight-Ridder/Tribune Information Services. >CP 1232ES 12-05