But their children have medical conditions so rare, doctors don't have names for them yet, reports correspondent Vicki Mabrey.
The Amish make up only about 10 percent of the population in Geagua County in Ohio, but they're half of the special needs cases. Three of the five Miller children, for example, have a mysterious crippling disease that has no name and no known cure.
Their father, Bob Miller, says he realizes there is a crisis in the community, which is why he and two other fathers, Erwin Kuhns and Robert Hershberger, have agreed to break a strict Amish rule that forbids them to appear on camera. The three sat for an informal interview.
The three Byler sisters were all born with a condition that has no cure and mysteriously leads to severe mental retardation and a host of physical problems. Last year, doctors figured out the girls have the gene for something called Cohen Syndrome; there are only 100 known cases worldwide.
Since then, more than a dozen other cases of Cohen's have been discovered in Ohio Amish country.
"Nobody knew it was around here and we found, what, 20 to 30 cases in this area now that they didn't realize. Nobody knew about it," says Erwin Kuhns.
But for so many years, the Amish have had no names for these disorders. It was simply a mystery why half the headstones in Amish cemeteries were headstones of children.
The genetic problems come down to something called the "founder effect" because the nearly 150,000 Amish in America can trace their roots back to a few hundred German-Swiss settlers who brought the Amish and Mennonite faiths to the United States in the 18th century. Over generations of intermarriage, rare genetic flaws have shown up, flaws which most of us carry within our genetic makeup but which don't show up unless we marry someone else with the same rare genetic markers.
Kuhns and Miller admit these conditions have gotten more widespread in recent years. So much so that concerned families pulled together, held an auction and raised enough to build a clinic within buggy range of all the Amish. They also hired a pediatrician and researcher named Dr. Heng Wang to start caring for their children.
Kuhns' daughter isn't doing well at the moment, but now he can take her to the clinic every day, if needed, and the doctor has even made house calls at his home.
While 60 Minutes Wednesday was in Ohio, Dr. Wang made a house call to check on the Miller children. Bobby Junior, the sickest, can't tell Wang what's bothering him because he can't even talk.
And the doctor was treating these challenging cases under the most rudimentary conditions since Amish custom prohibits electricity. Still, he doesn't complain. In fact, he calls the heritage beautiful and says, "We are not come here to change them."