The multitude of symptoms is one of the reasons that mitochondrial diseases like MERRF are often misdiagnosed, as Brittney's was, before a genetic test can confirm the true nature of the illness. Most treatment is centered on managing symptoms, such as with anti-seizure medications or blood sugar control in the case of diabetes.
"With genetic medicine, we know exactly what the problem is, but we can't make even an educated guess as to what the medicine should be," said Dr. Jeff Nobels, professor of Neurology, Neuroscience, and Molecular Genetics at Baylor College of Medicine in Houston. "Maybe it hasn't been invented yet."
Attending school and participating in extracurricular activities have been an important way for Brittney and Taylor to cope with their disease.
Both girls attended high school and took therapeutic horse riding lessons. Brittney was particularly fond of dogs and volunteered at the local humane society. Family trips included canoeing with alligators in Florida and swimming with sharks in Hawaii.
"Despite their medical situation, they're just kids, they're teenagers," Ramey said. "Those people really supported the girls. As much as we tried to provide for them, the community did as well."
A woman Ramey said he had never met before came to the family's home the day before Brittney died with two roasted chickens, two hams, five three-pound packages of ground chuck and eight packs of Ballpark Franks, the family's favorite brand.
"That was a powerful moment," Ramey said. "That a total stranger just wanted to help out because she recognized the pain and grief we were going through."
The mystery woman was not the only one who came to the Ramey's house bearing food and condolences. Ramey said people have been coming to see the family at home and in the hospital for about a week.
Though she is about two minutes younger than her twin, the course of Taylor's MERRF is progressing roughly one year behind Brittney's schedule. Her first seizure occurred 15 months after Brittney's, and she was diagnosed and treated properly right away.
Gary said she can walk a little bit but is still mostly wheelchair-bound. Her ability to speak, though affected, is better than her sister's, though Taylor is legally blind.
"[Taylor] sees that practically everything her sister went through, she's going to go through. I think that's an awful hard burden to carry," Ramey said. "On the flip side, she's a pretty happy child. She's going to the prom. We've not restricted them in any way."
Colclasure concurred that everyone familiar with the Ramey family is doing what they can to keep the girl's spirits high.
"Everyone's trying to keep [Taylor] busy," she said. "Not let her sit home and be sad."
While there are no treatments for mitochondrial diseases, including MERRF, DiMauro said researchers are experimenting with techniques to bypass mutated gene sequences or increase the number of healthy mitochondria in the body before the fatal, critical mass of mutated mitochondria is reached.
"Things are moving, but they are moving slowly," DiMauro said.
Despite the ordeal, Ramey insists that good things have come from his daughter's diseases, including how close the family is, and that education about the disease is extremely important.
"It doesn't mean the end of the world," Ramey said. "You have a choice to let the disease rule you, or you rule the disease.
"You can have a fruitful life. Maybe it's not as long as you'd like, but you can still reach for it."