COYOTE CANYON, N.M. — As Tina Golbe prepared to take her 15-year-old daughter, Laronda, outside, she covered the girl’s scarred face with a purple blanket to block out the fierce New Mexico sun.
Laronda’s dad, Larry, carried the 53-pound girl out to a truck with darkly tinted windows. Laronda let out a low wail.
Her mom — who can read her cries — said she was laughing, not crying. For a moment, Laronda let the blanket fall away and turned her face to the sky.
“They tell us, we don’t know how much longer we’ll have her,” Tina Golbe said. “We know it’s going to be soon. We know she’s not going to be with us very much longer. That’s always on our minds.”
Laronda has spent almost every moment of her 15 years hiding from direct sunlight, only venturing outside at night or under protective cover. She can neither walk nor talk and is fed through a tube.
She has a rare disease called xeroderma pigmentosum, or XP, that causes skin cancer from exposure to sunlight and, in severe cases — like Laronda’s — neurological degeneration.
Except, as it turns out, it may not be as rare among Navajo people. While the disease occurs in about one in 1.25 million live births in the U.S., it affects Navajo at more than five times that rate.
Some geneticists say the reason may stem from a dark period in U.S. and New Mexico history, when the U.S. Army, led by Kit Carson, force-marched the Navajo 450 miles in 1864 on what is known as the Long Walk, then interned them for four years at Bosque Redondo, nearly decimating the population to about 5,000.
At the same time, small pockets of Navajo hid away from the U.S. government. One or both of those events may have created what is known as a genetic bottleneck — which can cause some diseases to appear more frequently in the population.
“It sounds to me like there have been 10 or 12 cases (of XP) in the eastern reservation, which would be a huge concentration for that small population there,” said Robert Erickson, a professor of pediatrics and genetics at the University of Arizona, who published a paper on the Long Walk theory.
Neither treatment nor cure
The Golbes have already lost two children to the disease, for which there is no treatment and no cure.
Their first son, Lance, was jaundiced when he was born. Doctors put him under a purple light, and his skin burned to a bright red. At 18 months, they had a biopsy done and learned he had the disease.
Then, Tina Golbe got pregnant again. They were told there was a one in four chance each child would have the disease.
“We said ‘No, we didn’t want to terminate the pregnancy if we did have another child with XP,’ ” Golbe said. “We already had one, and we’d know how to take care of her.”
Their second child, Ladonya, didn’t have it. But their next two children, Laronda and Lane, did.
“After that, we just decided not to have any more,” she said
Lance died in 2002 at age 11. Lane died in 2011 at age 12.
The Golbes knew of two other families in Farmington who had children with the disease. They also met the Nez family, who lives on the Navajo reservation east of Gallup and had two children with XP.
Dorey and Yolanda Nez were featured in a PBS documentary called “Sun Kissed,” about the death of their daughter, Leanndra, and their search for answers about the disease. It aired in October.
They wondered why so many Navajo families had the rare disease.
“At the time we found out our kids were diagnosed with XP, there was little information about the diagnosis,” said Yolanda. “It was all detrimental, bad news after another.”
The medicine men had their own theories for what went wrong.
Maybe, it was the fact that they burned ants as kids, they said. Or maybe it was because their mothers looked at the eclipse when they were pregnant.
“Then they’ll, I don’t know, look in your soul, I guess,” Dorey Nez said. “Tell you what you did wrong when you were still in your mother’s womb. What your mother did is affecting you. It kind of keeps snowballing bigger and bigger. There’s no end.”
He added: “That’s why we just figure, we want facts.”
A doctor at University of New Mexico School of Medicine first suggested to the Nezes that the disease’s frequency may trace back to the Long Walk and the small groups that hid out.
The bottleneck theory works this way: When a population is drastically reduced, it creates a limited number of recessive genes. That increases the likelihood that the mutation will proliferate as the population begins to grow again.
Dr. Robert Erickson posits that there may have been three bottlenecks in Navajo history — including crossing the land bridge into North America and the migration to the southwestern U.S. — but the most recent was the Long Walk.
This is not unique to Navajos. Genetic bottlenecks are seen among Finnish, Amish, and Ashkenazi Jews, among others. XP, in particular, is more common among the Japanese than other populations.
“The unique concept here may be that the Long Walk did put them through the bottleneck,” said Dr. Randall Heidenreich, chief of the division of genetics/dysmorphology at the UNM medical school. “One individual, two individuals, it’s hard to know, actually carried the XP gene, and then their descendents also had that. By chance, they’re meeting up again.”
But Jeffrey Long, a professor of anthropology at UNM who studies population genetics, is not convinced by the Long Walk argument. The Navajo population declined to about 5,000, but he says that may not be a small enough population to explain an increase in disease prevalence.
It is possible, and maybe more likely, he said, that the gene for XP became prevalent in one of the earlier bottlenecks.
Last weekend, the Golbes drove their daughters — Laronda and Ladonya — from their home in Farmington to visit the Nez family in their mobile home on the Navajo reservation.
The two families met because they both had children with XP. Yolanda Nez, an advocate at the Native American Disability Law Center, gives presentations about the disability. One day, someone told her about the Golbes.
Their stories are similar.
The Nez couple had two children, Leanndra and Darnell. As a baby, Leanndra’s face, arms and hands would burn when they took her outside. The doctors didn’t know why it was happening, until one referred them to a dermatologist at UNM, who diagnosed her with XP.
Then, Yolanda got pregnant with Darnell. He had the disease, too.
They covered their windows with tinted material and thick curtains and blankets. They began going grocery shopping and taking walks at night. They took the children to a special camp in New York for children with XP. They got them sun-protective suits from NASA to wear outside. Leanndra went to Albuquerque for more than 41 skin biopsies.
“I stopped counting after 41,” Yolanda said.
Darnell deteriorated more quickly then Leanndra. He never walked or talked. He died in 2005 at age 11. Leanndra died in 2009 at age 16.
“It’s relentless,” said Dr. Leslie Morrison, a UNM professor of pediatrics and neurology. “The neurological deterioration then begins to involve loss of motor function, progressively and fairly rapidly, as well as loss of language. There is what’s called sensorineural hearing loss over time and even loss of sensation in the skin.”
Dorey stayed home with the kids when they were sick — getting them ready for school, feeding them, changing their diapers — while Yolanda worked.
Now, the house is quiet.
“It doesn’t get any easier,” he said. “It’s been two years. The longer it is, the harder it gets.”
The Nezes want more genetic testing done on the reservation. The Navajo Institutional Review Board has never approved a genetic study, although it is allowing a DNA screening for severe combined immunodeficiency, or SCID, Erickson said.
“The more people get tested, then you have more information,” Dorey Nez said. “When you have more information, now we can start thinking about how we can approach it. Maybe, there’s cures. Or, maybe, there’s something.”
Morrison said if the specific gene mutation among the Navajo patients were identified, it could be an avenue for treatment.
“This is a disease where if you knew the child had the disease from birth, that would be a chance to implement therapy for them, before they then develop the devastating neurological features of the disease, because they’re so intact in the beginning,” she said.
Doctors have asked Yolanda and Dorey Nez if they want to serve as a support network for families with XP.
“I could. I was lost once,” Yolanda said. “I have one foot in the door and one foot out. With my own kids, I knew what to do. I knew my role. I was always a mom first and then always an advocate second. I think right now I’m just trying to get better, too.”