Ted Tiller gets around his Huntington home in a wheelchair, battling a rare disease that has left him with weakened legs, brain lesions and failing vision.
Since 2009, Tiller, 23, has suffered from mitochondrial disease, a debilitating, often-fatal condition that affects how energy in the body is generated.
Now, on his left wrist, Tiller wears a green band representing the need to conquer his mitochondrial disease.
"It's hard to deal with but I've done that for years," said Tiller, who was forced to leave his studies at Nassau Community College when the disease first appeared in 2009. "I've had nurses for two years."
His speech has become so difficult to understand that his mother interprets his words for visitors.
Mitochondrial disease is really a bundle of different conditions, and Tiller's symptoms indicate he has at least one form of the disease called MELAS, an acronym for problems that include weakened limbs, strokes, seizures, loss of vision and hearing, and kidney deterioration.
Each year, up to 4,000 children in the United States inherit mitochondrial diseases, according to the United Mitochondrial Disease Foundation in Pittsburgh. Mitochondria -- tiny compartments inside cells -- generate energy for the body.
Now, scientists want to use high-tech human embryos produced in a lab with genetic material from three people -- a father, a mother and a second woman -- to keep children from inheriting the disease. Mitochondrial material from the second woman would replace a mother's unhealthy mitochondria.
But in their quest for a cure, scientists have clashed with bioethicists -- some fearful that changing the genetic makeup of human eggs or embryos will endanger the health of future generations.
"A lot of questions are being raised saying we don't know what's going to happen," said Sheldon Krimsky, Lenore Stern professor of humanities and social sciences at Tufts University.
"Not only do you have to have really good clinical trials to show that it's safe -- if you're going to breach the germ line [genetic material passed on to offspring], is this the ethical case in which to do it?" Krimsky asked.
Researchers in the United States and Britain want government officials to let them implant the high-tech embryos in women for the first time.
Britain is expected to act by the end of this year. The Food and Drug Administration held a two-day hearing in February but has made no decisions.
Fear of 'designer babies'
Some opponents say children who would develop from the embryos would be "three-parent babies" and might pass on disease or genetic mutations to future generations.
And some bioethicists wonder whether allowing the implantation of the embryos might lead to separate efforts to make "designer babies" with traits selected by parents wealthy enough to ask doctors to craft the baby of their dreams.
Others take a more moderate stance. Nita Farahany, a professor at Duke University's Institute for Genome Sciences and Policy and a member of President Barack Obama's Presidential Commission for the Study of Bioethical Issues, said questions about the safety of the process must still be answered.
"It's a practical concern but it's also an ethical concern," Farahany said in an interview.
However, Farahany said concerns about "designer babies" don't apply. "It's disappointing to me that people have such little faith in our ability to draw lines," Farahany said.
The embryos would not prevent all inherited mitochondrial disease because there are no simple tests to detect it before birth.
Only women carry the disease. Mothers who don't have the disease but are carriers usually don't know it until they give birth to a child who develops symptoms -- sometimes not until adulthood.
However, if a first child were to develop early symptoms, parents could use the high-tech embryos to prevent disease in other children.
That hasn't changed some minds. "The issue of crossing this bright line in policy observed by scientists around the world is such a huge step," said Marcy Darnovsky, executive director of the nonprofit Center for Genetics and Society in Berkeley, California. She wants more scrutiny before allowing use of the embryos in women.
Scientist Shoukhrat Mitalipov, director of the Center for Embryonic Cell and Gene Therapy at Oregon Health & Science University, is one of those who want to conduct clinical trials by implanting embryos in women.
Mitalipov has produced human and monkey embryos in his lab, changing the genetic makeup of eggs through mitochondrial transfer -- a modified version of in vitro fertilization, a method used to help women become pregnant. The human embryos were not allowed to grow and were not implanted in women, Mitalipov said.
Mitalipov's work in monkeys produced five healthy babies with no signs of mitochondrial disease. The first two monkeys, males named Mito and Tracker, were born in 2009. Crysta, the fifth monkey and first female, was born in 2012.
"We tested not only feasibility but we also tested its safety," Mitalipov said.
Using a mother monkey's egg, Mitalipov removed the nucleus, which contained 99 percent of her DNA. He left behind the mitochondria, which can cause the disease.
The mother's nucleus was then transferred to a female donor's egg -- whose nucleus had been removed.
The donor's egg contained healthy mitochondria.
The egg was then fertilized with sperm from a father monkey, forming an embryo that was implanted in the mother.
Mitalipov says he does not alter the makeup of the nucleus, so his procedure would not affect human traits influenced by nuclear DNA.
He says if he were allowed to implant modified human embryos, they might pass on a tiny amount of donor mitochondrial DNA -- controlling energy production -- but the babies would be largely the product of mother and father. "I understand some of the worries," Mitalipov said recently in an interview. "It's kind of a new horizon. This is not about designing a baby or genetic enhancement."
In the late 1990s, a team of New Jersey scientists used a procedure similar to Mitalipov's to help women become pregnant.
Embryologist Jacques Cohen led the team at St. Barnabas Medical Center in Livingston.
Cohen used a process called cytoplasmic transfer -- moving donor cytoplasm containing mitochondria into a mother's egg. The cytoplasm and mitochondria exist outside the egg's nucleus.
Seventeen babies resulted from Cohen's work.
Cohen found mitochondria from mother and donor in two of the children at age 1.
In addition, one fetus was aborted and a pregnancy ended in miscarriage. Evidence of Turner syndrome -- a chromosomal condition that affects development in females and most commonly causes short stature -- was found in both cases.
Recently, in response to emailed questions from Newsday, Cohen estimated that worldwide, 40 to 50 babies have been born using cytoplasmic transfer.
In China in 2003, doctors reported transferring a nucleus from one woman's egg into the egg of another. The woman had twins who died after a premature birth. China later banned the technique.
Cohen also said in his email that many years ago, he considered using the same kind of procedure Mitalipov has used. "It is an intriguing possibility and has the potential to cease generational transmission of a host of devastating diseases," he said.
Call for public discussion
Diseases such as Alzheimer's and amyotrophic lateral sclerosis (Lou Gehrig's disease) have been found to have mitochondrial links.
In 2001, after Cohen reported on his work, the FDA prohibited use of the embryos in women.
Bioethicist Thomas Murray, president emeritus of the Hastings Center bioethics think tank in Garrison, upstate New York, said the United States needs "a broad and engaging public discussion" about genetically modified embryos.
"I think if you're going to make a child, the well-being of that child and circumstances of that child matter a great deal," Murray said.
Murray served on President Bill Clinton's bioethics commission and has suggested that Obama's bioethics commission study the question of the embryos and related issues.
Dr. Joshua Klein, an assistant obstetrics and gynecology professor at Icahn School of Medicine at Mount Sinai in Manhattan, teaches residents at South Nassau Communities Hospital in Oceanside.
"I think it [Mitalipov's work] should go forward in a setting of informed consent," Klein said.
Dr. Avner Hershlag, chief of the human reproduction center for the North-Shore-Long Island Jewish Health System, said, "How we make sure that what you are transferring is safe and healthy remains to be seen."
Meanwhile, Ted Tiller is taking vitamin cocktails to keep his disease from advancing. He goes to a gym to do special exercises, uses a ventilator to breathe at night and has raised thousands of dollars for the United Mitochondrial Disease Foundation.
He also writes poetry and has published a book, "Dreamers versus Nightmares." Proceeds go to PULSE of New York, a Long Island patient safety group.
Neither Tiller nor his mother, Mary Brower, are convinced that high-tech embryos are the best way to attack mitochondrial disease. Brower asked, "How do you know what might manifest in the long run? "
The first name of Ted Tiller, who lives in Huntington and has mitochondrial disease, was misspelled Friday in a caption.