Alyssa Turner, 13, looks a lot like Karli Humphrey, 14. She also looks like the little girl featured on the brochure for the Cornelia de Lange Syndrome Foundation.

Actually, it is often distinctive physical traits that send doctors in the right direction when it comes to diagnosing the rare genetic condition, called CdLS. Those with the syndrome tend to have small hands and feet, thin eyebrows that arch and meet, long eyelashes, upturned noses and downturned lips. They are typically very petite and thin. They may have partial joining of the toes, and about one-fourth of them have limb differences or missing arms or legs or fingers or toes.

Other similarities are not visible but very real. Among the most common are reflux, bowel abnormalities, heart defects, seizures, problems feeding, cleft palate and speech and hearing challenges. Developmental delays are common, but like the other symptoms, they vary a lot. Some of the children are very mildly affected by the genetic condition, while others, like Maeve Barnett, have a very severe form. She died at age 5 months.

CdLS affects around one in 10,000 live births, the result of genetic mutation after conception. So far, three genes have been discovered that can lead to CdLS, and there may be more. In Utah, the foundation has identified about two dozen families with children who have the syndrome, although they believe there may be as many as 10 times that many, who either haven't been diagnosed or haven't contacted the foundation for information and support services.

When Leila (pronounced Lee-ila) Turner was pregnant, she and her husband, Allen, of Layton, were told the baby wasn't growing as fast as most babies. But a nonstress test shed no light on why. Alyssa was born two weeks early, and the pediatrician, looking at her, said there was "something different about her," Leila remembers. Besides being obviously small — 4 pounds, 12 ounces — her ears were set low on her head and her lips turned down at the outside edges.

They ran tests, but it was a neonatalogist visiting from Minneapolis who recognized the syndrome.

Alyssa was in the intensive care unit for a few days learning to eat, which is often hard for children with CdLS. At home, she had severe reflux, the biggest medical challenge the family has faced with her and one that also often creates dental problems for children with CdLS. On the mild to severe scale, says her mom, Alyssa's about in the middle.

She doesn't speak but has learned to sign about 150 words. She's about the size of her sister Corrine, who's 8. She's still growing, but "they develop slowly both physically and mentally," her mom says.