Rare Growth Disorder in Ecuador Offers Cancer Prevention Clues

In the Andean valleys of southern Ecuador, in a town called Piñas where eight thousand people live scattered across the mountainside, there exists an unusual concentration of people with a rare genetic condition that stops their bodies from growing beyond four feet tall. Laron syndrome, a growth disorder caused by the body's inability to use the growth hormone it produces, has drawn the attention of researchers worldwide—not because of the condition itself, but because of what it might teach us about preventing cancer.

María Luísa Romero and her twin sister, María del Cisne, both live with Laron syndrome. They sit together on a sofa and speak about the weight of it: the stares, the isolation, the daily challenges. But they also speak about strength—about pooling their resilience, about defending each other. "We're always strong," María Luísa says. "One defends the other." For decades, they have had each other. What they did not have was an explanation for why their bodies seemed to resist diseases that afflict so many others.

That explanation began to emerge from the work of Dr. Jaime Guevara, an endocrinologist who has spent forty years studying Laron syndrome in Ecuador. Over a twenty-two-year period, his team tracked roughly one hundred people with the condition and compared them to sixteen hundred relatives of normal height living in the same villages. The numbers were striking: among those with Laron syndrome, there were zero cases of diabetes and only one case of non-fatal cancer. In the control group, five percent developed diabetes and seventeen percent developed cancer. The researchers concluded that the difference came down to a single hormone: IGF-1, insulin-like growth factor 1. People with Laron syndrome cannot produce it. Their bodies lack the chemical messenger that, in most people, may prevent cancer cells from undergoing apoptosis—the process by which damaged cells die.

Dr. Guevara partnered with Dr. Valter Longo, a specialist in aging from the University of Southern California, to explore whether this protective mechanism could be replicated in people without the syndrome. "The idea is to be able to replicate, through a drug or a diet, what happens in people with Laron syndrome, in other people without the syndrome," Guevara explained. "It would be a great contribution from this wonderful community to the world." The research has drawn international attention. Prof. Zvi Laron, the Israeli pediatrician after whom the syndrome is named, has studied seventy patients in Israel over fifty-eight years and observed similar protection against cancer. A comprehensive research paper documenting all known cases of the mutation identified between 1966 and 2025 is being published this month.

The condition itself is rare. Globally, only eight hundred and forty people are known to have it. The concentration in Ecuador is the result of history: the mutation originated thousands of years ago in Indonesia and traveled west along merchant routes. Sephardic Jews carrying the mutation later migrated to the Americas, settling in isolated areas where generations of intermarriage created the high incidence now seen in the provinces of El Oro and Loja. For the twins, living among others with the syndrome has been a lifeline. "We can tell each other about the things that happen to us, the good and the bad, because we definitely share many of the challenges we have to face every day," María del Cisne says. When they left Piñas to study elsewhere, the isolation was brutal. "They had never seen short persons like us there, so everyone looked at us strangely. They pointed at us. It was odd."

But the research findings brought false hope. Two years ago, María del Cisne was diagnosed with colon cancer. She underwent surgery and chemotherapy. The diagnosis shattered the assumption that the syndrome conferred immunity. "That made us realise that we weren't, as we thought, completely immune to these diseases," the sisters said afterward. "We had to take care of ourselves, we had to exercise, we had to watch what we ate." Prof. Laron himself acknowledges that IGF-1 levels account for only part of the explanation. Even Laron patients who received IGF-1 treatments as children to help them grow did not develop cancer, suggesting other protective mechanisms are at work. Research on mice and pigs continues.

For children born with Laron syndrome today, there is a drug called Increlex, developed fifteen years ago, which can increase height if given during growth spurts. But access is severely limited. The drug costs more than eight hundred dollars per bottle and is produced by only one pharmaceutical company. A child needs at least three bottles per month—twenty-four hundred dollars monthly. In Piñas, a two-year-old named Camila was supposed to start treatment six months ago but has not yet received her first dose. Her mother, Mayra Loaiza, worries about what this delay means for her daughter's future. "I want my daughter to have as normal a life as possible. I don't want her to be discriminated against because of her size." The twins, now forty, missed the window for treatment entirely. They have made peace with their stature, but María Luísa carries a quiet regret: "The treatment would have saved us a lot of heartache." Yet the research continues, and with it, the possibility that what Laron syndrome teaches us about growth hormones and cancer might one day protect millions of people who will never have the condition themselves.