Measuring UpSeveral years ago, when Jonelle Hernandez Zepeda wondered if her son’s growth was normal, she came up against a frustrating problem: There was no solid reference point. Max, now 5, has Down syndrome, which means he grows at a rate different from that of a typical child — and the most recent growth charts for children with Down syndrome were developed almost 30 years earlier.

Since that time, clinical care for children with Down syndrome has changed enormously, bringing an array of benefits. Their life expectancy, for example, has increased from 35 years in 1985 to 53 years in 2007. Have growth patterns changed, too?

Zepeda now has the answers she needs, and her family played a role in uncovering them. For four years, researchers at The Children’s Hospital of Philadelphia have led the Down Syndrome Growing Up Study, which gathered information about contemporary growth patterns of children with Down syndrome. Most of the 637 children in the study, including Max, were patients in CHOP’s Trisomy 21 Program, one of the largest and most comprehensive in the country, serving individuals from birth through adulthood. (The program’s name comes from the extra copy of chromosome 21 that causes Down syndrome.)

The study team, led by Babette Zemel, PhD, director of the Nutrition and Growth Laboratory at CHOP, took precise measurements. As a result, pediatricians and parents can see where a child’s height and weight stand relative to their genetic potential.

“The families and the kids were so enthusiastic and appreciative that we were doing this project,” Zemel says. “They knew that there was a problem with the old growth charts, and they really wanted to be a part of fixing it.”

One of the study’s major findings is that infants with Down syndrome are growing much better when compared with the old growth charts. Children under age 3 show marked improvements in weight gain, and males age 2 to 20 show gains in height.

“We were thrilled to participate, even though it meant extra trips to CHOP,” says Zepeda. “We love CHOP, and we love the Trisomy 21 Program.”