Turner syndrome affects females and occurs because of the partial or complete absence of the second X chromosome. Girls and women with this condition experience decreased growth because one of the genes that regulate growth, known as the SHOX gene, is found on the very ends of the X chromosomes. Because females with Turner syndrome do not have a second X chromosome, the SHOX gene is often missing. Although girls with this condition do not have a deficiency of growth hormone, clinical human growth hormone studies indicate that treatment with hGH can help them overcome short stature.
Dr. David K. Stephure and his colleagues conducted a controlled trial of growth hormone supplementation in girls who had short stature due to Turner syndrome. They selected 154 girls with Turner syndrome and randomly assigned them to two groups. One group received growth hormone injections six times per week. The control group received no growth hormone treatment. Girls in both growths received sex hormone replacement therapy starting at 13 years of age. Of the 154 that started the study, 104 completed it and 50 dropped out. At the conclusion of the study, investigators determined that human growth hormone supplementation and therapy with sex hormone replacement increases the adult height of females who have Turner syndrome. The results of this study appeared in a 2004 issue of “The Journal of Clinical Endocrinology and Metabolism.”
Prader-Willi syndrome results from an abnormality of chromosome 15. It occurs in males and females, with the Prader-Willi Syndrome Association estimating that it has a prevalence of one in 15,000. This condition causes short stature, weak muscles and abnormal metabolism. Because children with this condition burn far fewer calories than normal, Prader-Willi syndrome is the most common genetic cause of morbid obesity in children. Children with this syndrome experience chronic feelings of hunger and increased appetite.
Researchers started studying the use of growth hormone therapy in children with Prader-Willi syndrome in 1981. In a critical appraisal of the use of hGH in patients with Prader-Willi syndrome, Dr. David B. Allen and Dr. Aaron L. Carrel indicate that growth hormone therapy improves physical strength, growth and agility in children with Prader-Willi syndrome. hGH therapy also increases final height in children with this genetic disorder. Allen and Carrel also caution that additional research is needed to determine the risks and long-term benefits of this type of therapy. Their appraisal appeared in a 2004 issue of the “Journal of Pediatric Endocrinology & Metabolism.” In June 2000, the Food and Drug Administration approved growth hormone for the treatment of Prader-Willi syndrome.
Growth Hormone Deficiency
In children with growth hormone deficiency, the pituitary gland does not produce enough growth hormone. Because children need this hormone for proper growth, growth hormone deficiency leads to short stature and improper growth of muscle and bone. This condition may also cause fatigue and lack of motivation. Other symptoms include increased fat around the waist, delayed dental development and a delay in the onset of puberty. Adults who develop this condition due to pituitary tumors experience a lack of energy, loss of muscle mass, anxiety, dry skin and weight gain around the waist.
In December 2010, the Food and Drug Administration released a notice regarding the results of a study conducted in France. The study, titled Sante Adult GH Enfant (SAGhE), found that some people treated with synthetic human growth hormone during childhood had a small increased risk of death when compared with those who did not receive this treatment. As of March 2011, the FDA had not finished reviewing the results of the study, so it is unclear how the results will affect the future use of growth hormone in children with this deficiency.
Chronic Renal Insufficiency
Chronic renal insufficiency, also called chronic kidney disease, has several causes. Damage to the blood vessels that supply the kidneys leads to reduced blood flow to these vital organs, resulting in kidney disease. Damage to the kidney tissue from trauma also increases the risk of kidney disease. Urinary obstructions may block the flow of urine from the kidneys to the bladder, which causes urine to back up into the kidneys and damage the kidney tissue. In children with chronic kidney disease, growth retardation occurs because chronic kidney disease affects how the body uses and responds to human growth hormone.
Because human growth hormone studies on the effects of hGH in children with kidney disease are limited, two researchers conducted a literature review to determine how hGH therapy affects children with chronic renal insufficiency. Shefali Mahesh of Albert Einstein College of Medicine and Frederick Kaskel of Children’s Hospital at Montefiore wanted to understand more about how chronic kidney disease affects growth failure in children. They also wanted to find out about new evidence supporting hGH therapy in children with growth failure due to chronic kidney disease. Their review supports the idea that the presence of chronic kidney disease leads to growth hormone resistance. They also report that, despite hGH therapy, final adult height in children with this type of resistance is often below their target heights. The results of their review appeared in the journal “Pediatric Nephrology.”
Turner Syndrome Society of the United States: Growth in Turner Syndrome
The Journal of Clinical Endocrinology & Metabolism: Impact of Growth Hormone Supplementation on Adult Height in Turner Syndrome: Results of the Canadian Randomized Controlled Trial
Prader-Willi Syndrome Association: What is Prader-Willi Syndrome?
Journal of Pediatric Endocrinology & Metabolism: Growth Hormone Therapy for Prader-Willi Syndrome: A Critical Appraisal
eMedicineHealth: Growth Hormone Deficiency
U.S. Food and Drug Administration: FDA Drug Safety Communication: Ongoing Safety Review of Recombinant Human Growth Hormone (Somatropin) and Possible Increased Risk of Death
Pediatric Nephrology: Growth Hormone Axis in Chronic Kidney Disease