Craig Benson thought his 5-year-old daughter just needed eye glasses when she complained about not being able to see the television set in 2008. But after consulting specialists, the family learned their beautiful daughter had a fatal neurodegenerative disorder -- Batton disease.
"In an instant, a word we had never heard of changed everything," said Benson, 48, and CEO of an Austin, Texas, biotech company. He and his wife Charlotte never knew they were carriers of the rare disease.
Christiane, now 8 and legally blind, faces a grim prognosis: seizures, memory loss and finally death by her late teens or early 20s. She is one of about 700 other Batton cases in the country.
Rare diseases account for 20 percent of all pediatric mortalities in the United States, according to the Beyond Batton Disease Foundation, the nonprofit Benson founded after his daughter's diagnosis.
But now, largely because of Benson's passion, a new DNA test has been developed to detect parents who are carriers of 580 of the most severe inherited childhood diseases -- not only Batton, but muscular dystrophy, immune deficiencies like the "Bubble Boy" syndrome and Pompe disease, described in the 2010 film, "Extraordinary Measures."
The test, which was announced in the journal Science in Translational Medicine, uses genetic sequencing to identify recessive mutations before a couple decides to become parents.
The average person carries at least two to three gene mutations that can cause disease. When both have the same mutation, the chance of having an affected child is 1 in 4; the risk of having a child who is a carrier is 2 in 4; and the odds of having a normal child is 1 in 4.
The carrier screening test is cheap -- less than $400 for hundreds of conditions -- and could be marketed in the near future, according to Dr. Stephen Kingsmore, now a physician-researcher at Children's Mercy Hospital in Kansas City, Mo., where clinical work will be done.
"The long-term impact could be phenomenal," said Kingsmore, who headed up the research at the National Center for Genome Resources in Santa Fe, N.M.
The test will be sold through Benson's foundation to eventually find cures -- a kind of "venture charity," he said.
Right now, preconception testing is recommended for just a few diseases -- like Tay-Sachs and cystic fibrosis -- and can cost as much as $2,000 each.
If the Bensons had access to this test, they might have decided to adopt, turn to in vitro fertilization and test the embryos before implantation or seek egg and sperm donors.
Their 6-year-old son Garland, who was conceived before Christiane was diagnosed, is healthy and not a carrier.
The test will likely be a blood test and later a simple swab of the cheek. Egg and sperm banks may be the first industry to adopt the testing to screen potential donors.
The test is a boon, even for those who are carriers and decide to take the risk and get pregnant so treatment can begin sooner.
"Some will go ahead and plan a family," said Kingsmore. "But let us prepare for the potential they may have a sick child and get them into a network of support or at least make those introductions when the baby is born so they don't feel hopeless and helpless or lost in the world."
Elizabeth Joshi of Evansville, Ill., could have been helped by this test, as she spent months trying to get a diagnosis for her son with Joubert syndrome, a rare genetic disorder that affects the brain's cerebellum.
Though it can vary in severity, it causes breathing problems, seizures and often fatal kidney disease. Only about 650 families in the U.S. are affected.
"Not knowing what was wrong with him hit me like a ton of bricks," said Joshi, 40, and a former lawyer.
Shaan, now 6, is unable to eat solid foods and cannot speak or walk. How long he will live is "a big question mark," according to his mother.
"He seems very aware of what's going on," said Joshi. "But it's so hard on him physically for him to express what he needs and wants and leads to a lot of aggravation for him. It's a daily struggle."
Shaan's 8-year-old sister in unaffected, but Joshi has decided not to have any more children.
"We are personally not willing to roll that dice," she said, "knowing what he deals with."