Coping With Rett Syndrome
A debilitating disorder that strikes only girls, Rett Syndrome challenges
physicians, patients, and families. One symptom of Rett Syndrome is profound
growth failure. Pediatrician and nutritionist Kathleen J. Motil with the
USDA-ARS Children's Nutrition Research
Center (CNRC) in Houston, Texas, is finding innovative ways to promote adequate
nutrition, improve health, and enhance growth for some of these patients.
Rett Syndrome occurs in 1 out of 23,000 live births. The onset is baffling:
A healthy, active infant gradually stops developing normally. Typically, she
regresses, losing her speech and walking skills, as well as the ability to play
with toys. Repetitive hand-wringing and hand-washing movements are common, as
are breathing abnormalities. Growth failure and muscle wasting may occur as
early as 1 year of age. Motil and others have done studies suggesting this poor
growth and wasting may be linked in part to the girls' need for special
Andreas Rett, the medical doctor who first described this neurodevelopmental
disease in 1966, noted the symptoms of wasting and slowed growth. Growth
retardation is one of the factors supporting the diagnosis of Rett Syndrome.
Other researchers, including Motil's colleagues, pediatric neurologist Daniel
G. Glaze and nurse practitioner Rebecca J. Schultz, have reported in medical
journals a deceleration in the rate of gain in head circumference, height, and
Studies in Norway, England, and the United States have suggested nutrition
and eating difficulties might be a possible cause of these decreased rates of
growth. Indeed, "Part of the problem is that these girls frequently have
oromotor dysfunction," says Motil. "They don't chew or swallow
properly, and their dietary intake is inadequate to support normal
Motil has had some success fitting her patients with a gastrostomy button, a
surgically implanted device that allows nutrients to be delivered into the body
while the girls sleep. One 7-year-old patient increased her weight from 31
pounds to 48 in a year. She gained enough strength to sit up by herself for the
While that sounds like good news, an average 7-year-old weighs about 60
In addition to helping patients, Motil is doing research to find out why
these girls aren't growing and have less muscle mass than their healthy
Part of her research involves comparing the metabolism and physiology of
girls with Rett Syndrome to those of healthy girls. For these experiments,
small volunteer groups of girls with and without Rett Syndrome spend brief
stays at the General Clinical Research Center at Texas Children's Hospital in
Houston and undergo tests at the neighboring CNRC.
Motil wondered whether the repetitive arm, hand, leg, and body motions
contributed to the development of malnutrition by burning calories that would
be otherwise used for growth. Research she published in the February 1998 issue
of Journal of Pediatrics showed that repetitive motions were not an
But Motil noted that there were metabolic differences between the girls with
Rett Syndrome and healthy girls. When sleeping or resting quietly, those with
Rett syndrome had total body metabolic rates 23 percent lower than normal.
"The lower metabolic rate was caused by a lower lean-body mass, or less
muscle mass," said Motil. "The lower body mass may be related to a
lower dietary intake."
Although the energy balance of calories consumed, minus calories used, was
positive in girls with Rett Syndrome, it was lower than that of age-matched,
healthy girls. It could be that a subtle, long-running, energy-deficit diet
hampered nutrition and growth.
In a more recent study published as an abstract in Pediatric
Research, Motil added to evidence that giving girls with Rett's syndrome a
liquid nutritional supplement via the gastrostomy button was helpful. The test
showed it increased body weight and reversed the downward trend of poor growth
"Nevertheless, we found that the supplements increased body fat much
more than lean body mass, even with the presumably adequate protein and energy
intake," said Motil. "Our next task is to understand why we are
unable to improve muscle mass to the same extent as body fat." By
Jill Lee, Agricultural Research
Service Information Staff.
This research is part of the ARS National Program on Nutrient Requirements,
Food Composition, and Intake described on the World Wide Web at
Kathleen J. Motil is with the
USDA-ARS Children's Nutrition Research
Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates
St., Houston, TX 77030; phone (713) 798-7178, fax (713) 798-7187.
"Coping With Rett Syndrome" was published in the
February 1999 issue of
Agricultural Research magazine.