Doctors say a new drug has shown success in treating the effects of precocious puberty--unusually rapid growth followed by stunted growth. The disorder is seen six times more often in girls than boys.
Researchers years ago found some children begin to mature sexually long before others. These children grow much faster than normal. Then, suddenly, bone growth slows to almost zero. This deprives them of added inches other children were gaining while waiting for puberty.
About half the girls with the disorder fail to attain an adult height of 5 feet.
To treat precocious puberty, doctors at Massachusetts General Hospital, San Diego's Salk Institute and the National Institutes of Health are delaying puberty with a drug derived from the naturally occurring gonadotropin releasing hormone (GnRH).
Produced in the brain, GnRH enables the pituitary gland to make hormones called gonadotropins. These, in turn, stimulate the testes to produce the male sex hormone testosterone and the ovaries to produce the female hormone estrogen.
The blocking agent, more powerful than GnRH itself, was developed by Dr. William F. Crowley of Massachusetts General's Vincent Research Laboratories, and colleagues at San Diego's Salk Institute and the developmental endocrinology branch of the National Institutes of Health.
"The drug has proven to be effective and reversible in more than 200 children treated in this country and elsewhere," said Crowley. "We have demonstrated that as these children are treated they outgrow their predicted height."
While too little time has passed to determine long-term side effects, the drug has been relatively free of significant short-term side effects.
Crowley expects the puberty-delaying agent also to help children deficient in growth hormone. While precocious puberty accounts for the short stature of one of 5,000 short adults, growth hormone deficiency affects about 50 times that number.
The continuing studies will also explore possible uses for the drug in countering growth loss caused by other disorders such as cystic fibrosis, diabetes and kidney disease.
"A child may lose a year or two of growth because of illness, but, unfortunately, puberty usually developes on time," said Crowley. "The new treatment may be able to hold off the puberty. We think the potential to enhance growth is tremendous."