We stop at a modest cinder block building perched on a hillside. There is no glass in the windows, nothing but a few plastic chairs inside. We are welcomed into the home of Narcisa Lois and her three children. Her husband, a farm laborer who supports the family on a few dollars a day, is away at work.
Guevara is quick to point out that the smallest of the children is not the youngest. Five-year-old Yoneli stands less than 2 feet tall, 4 inches shorter than her sister. Yoneli has Laron syndrome.
The rest of the family is of normal height. Yoneli's mother had no idea that both she and her husband carried the recessive gene that randomly surfaces to cause Laron Syndrome.
"The condition needs to have the father and mother who have the mutation," explains Guevara. It is passed on through inbreeding, which is very common in this remote tropical Appalachia. There is no mystery here: Narcisa and her husband are first cousins. "Isolation, that's the whole thing," says Guevara.
Twenty years ago, when Guevara began treating and studying the dwarfs of southern Ecuador, it was because he wanted to help them. But an interesting and quirky pattern started to emerge. He realized that there has never been a single incidence of cancer or diabetes among them.
"I start noticing that somehow in this area that we all know in Ecuador is an area with high rates of cancer, not one of these patients has ever died of cancer," he says. "And I'm talking about a total of 135 names that I can think of. None of them has ever died of cancer. To me the possibility that that is a coincidence is almost none, because every single family in this case has at least one or two or three relatives that have died of cancer."
Larons have historically lived extraordinarily long lives. There isn't a single community of small people here; they are scattered in towns and remote villages within 100 miles of the main city, Piñas. In these parts they are affectionately called Viejitos -- little old people -- because they appear to age prematurely.
Guevara took us to meet the oldest living Laron, an exuberant 85-year-old woman named Pastorita. Her traditional diet of farm produce has kept her healthy. Younger Larons are dying early because their small hearts can't handle the fats and cholesterol of the fast food that many prefer to eat.
We stop at a modest but well-manicured house outside the town of Balsas. Out walks Norman Apolo, normal in every sense, except he is less than 4 feet tall. He tells us he realized he had a growth disorder, at 6 or 7 years old, when was in primary school.
A husband and father of three, Apolo leads a remarkably normal life. He is a respected high school teacher and writer, and he maintains a small farm. Despite his stature, he can drive a car with extensions on the pedals.
Apolo says he was surprised to discover that there was a term for his condition.
"These are questions of nature, questions of God that I had not accepted," Apolo says. "There was always a possibility that I'd be OK."
Three hundred miles away in Quito, the capital, Guevara tracks his extraordinary patients from his offices at the Ecuador Institute of Endocrinology.