Solving Short: Genes, HGH and Surgery to Change Height

Scientists discover genes that determine height.

September 28, 2010, 1:23 PM

Sept. 29, 2010 — -- Being short certainly kills your chances for a basketball or modeling career, but social research suggests that shorter people also make less money, hold fewer leadership roles and are less sexually active than their taller peers.

For the most part, there is no escaping a short stature: Height is genetically predetermined, though scientists still don't fully understand how our genes control growth.

The most recent research, published Wednesday in the journal Nature, can still identify genes for only 10 percent of the variation in human height.

But for those born vertically challenged, would the world really be a rosier place if viewed from at least average height? Each year, many go under the knife, risking life and limb and tens of thousands of dollars, to find out.

For Kevin Kadakia, 23, now a third year medical student at the University of Miami, 5'2 was as tall as he was naturally going to get. His mother was short, so it didn't come as much of a surprise to him, but when given the opportunity to gain a full four inches through a leg lengthening orthopedic surgery, Kadakia decided to go for it.

"You don't get taken as seriously as someone of average height. It wasn't like I had low self-esteem, it was more of just trying to be normal as opposed to having a disadvantage," he says.

Days after graduating high school, the Oklahoma native flew to Baltimore to be operated on by Dr. Dror Paley, an expert in limb lengthening and reconstruction at St. Mary's Medical Center. The surgery broke the bones in Kadakia's upper and lower legs and implanted a system of bolts and braces that pulls the bones apart over a period of months, during which he couldn't walk and underwent extreme physical therapy.

"You don't realize what you're getting yourself into and the pain you're going to have to endure until you do it, especially as a teenager. But as I reflect back, I would do it again," Kadakia says.

Challenging Nature, Changing Heights

Surgical manipulation of the skeleton is the only way to boost height in adults, but endocrinologists have other ways of addressing height deficiencies in children, notes Dr. Joel Hirschhorn, a lead author on the recent Nature study and a paediatric endocrinologist at Children's Hospital of Boston.

"Most of the time when a child is growing slowly there's a familial tendency, but we don't understand much about what genes are involved," he says. The recent research, which drew on the genomes of more than 180,000 individuals, identified a hundred additional locations where changes in the genetic code could lead to differences in height.

"We're learning about human growth itself. From a better understanding of the biology to better therapy in individuals, that is at minimum a decade long process," he says.

At this point in time, children who are identified as having a growth problem are most often treated with medicines containing human growth hormone.

"It's the major hormone of growth in children," says Dr. Michael Yafi, an endocrinologist at University of Texas Medical School at Houston. "Parents usually have the idea that taller people in society have better chances in life, so they want their kids to be taller."

Break It to Make It: Growing Bone

Once the natural growing process is complete, as it was in Kadakia by age 16, human growth hormone cannot be used and surgery becomes the only option. With intense pain, months of grueling recovery and physical therapy, and the risk of complications and decreased function, this option is truly only for those determined to be taller.

The external approach used on Kadakia and an internal one that involves a telescoping rod both work by "breaking the bone and pulling it apart about a millimeter a day. Bone is a living substance so as you pull apart, it makes new bone to fill in the gap. As long as you go slowly, the limb will lengthen safely," Paley says.

The majority of Paley's patients are those who have a leg length difference or other deformity that can be corrected by leg lengthening. For the small percentage of people who see him for cosmetic reasons, "I can't improve their function like in others. The improvement that we get with these patients is purely body image."

A Potentially Dangerous Procedure

The increasing popularity in cosmetic lengthening, and its hefty price tag, has spawned many less-than-qualified surgical centers throughout the world that can often leave patients much worse off than when they started, Paley warns.

"Lengthening is a very dangerous thing to do unless you're very experienced with it," he says, noting that many patients come to him to fix the disastrous results of procedures done elsewhere.

For Kadakia, the procedure was a success and today he is fully recovered and stands 5'6", same as his dad.

The pain and long recovery was worth it, he says, and he would do it all again. He missed the first semester of college due to the procedure and after some complications barely made it to the second semester, still unable to walk at that point.

"People say that you change a lot in college, but I'm pretty sure the biggest change in my life was during my recovery time. I was short, but I wasn't a dwarf. When you see other patients around you who actually have genetic problems, it makes you appreciate what you have," he says.

One year away from his M.D., Kadakia said he is considering specializing in orthopedic surgery "just like Dr. Paley," though he hasn't decided quite yet.

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