Growth hormone deficiency - children

Causes

Short stature refers to any person who is significantly below the average height for a person of the same age and sex. This problem may happen if the person does not produce enough growth hormone. Growth hormone is produced in the pituitary gland, which is located at the base of the brain.

Most of the time, the cause of growth hormone deficiency is unknown.

It may be present at birth (congenital) or develop as the result of an injury or medical condition. Severe brain injury may also cause growth hormone deficiency.

Children with physical defects of the face and skull, such as cleft lip or cleft palate, may have poorly developed pituitary glands and decreased growth hormone levels.

Slow growth may first be noticed in infancy and continue throughout childhood. Your child's pediatrician will usually plot your child's "growth curve" on a standardized growth chart. The child's growth may range from flat (no growth) to very shallow (minimal growth).

Although it is uncommon, growth hormone deficiency may also be diagnosed in adults. Possible causes include:

• Tumors involving the pituitary gland or hypothalamus
• Brain radiation treatments for cancer
• Severe head injury

Symptoms

Children with growth hormone deficiency have a slow or flat rate of growth, usually less than 2 inches per year. The slow growth may not appear until a child is 2 or 3 years old.

The child will be much shorter than most or all children of the same age and gender.

Children with growth hormone deficiency still have normal body proportions, as well as normal intelligence. However, their face often appears younger than children of the same age. They may also have a chubby body build.

In older children, puberty may come late or may not come at all, depending on the cause.

Exams and Tests

A physical examination -- including weight, height, and body proportions -- will show signs of slowed growth rate. The child will not follow the normal growth curves.

Hand x-ray (usually the left hand) can determine bone age. Normally, the size and shape of bones change as a person grows. These changes can be seen on an x-ray and usually follow a pattern as a child grows older.

Testing for growth deficiency requires more than a simple blood test. Testing is usually done after your child's pediatrician has explored other causes of poor growth.

• Growth hormone causes the body to make insulin-like growth factor (IGF1) and insulin-like growth factor binding protein 3 (IGFBP3). Tests can measure these growth factors.
• Accurate growth hormone deficiency testings involves a stimulation test. This test takes several hours.
• MRI of the head can show the hypothalamus and pituitary glands.
• Tests to measure other hormones levels (lack of growth hormone may not be the only problem) may be done.

Treatment

Treatment involves growth hormone injections given at home. Patients often receive a growth hormone injection once a day.

Serious side effects of growth hormone therapy are rare. The most common side effects are:

• Headache
• Fluid retention
• Muscle and joint aches
• Slippage of the bones at the hip 

Outlook (Prognosis)

The earlier the condition is treated, the better the chance that a child will grow to be a near-normal adult height. Many children gain 4 or more inches over the first year and 3 or more inches during the next 2 years. The rate of growth improvement then slowly decreases.

Growth hormone replacement therapy does not work for all children.

Possible Complications

If left untreated, growth hormone deficiency will lead to short stature and delayed puberty.

Growth hormone deficiency may occur with deficiencies of other hormones, including the following:

• Thyrotropins (control production of thyroid hormones)
• Vasopressin (controls water balance in the body)
• Gonadotropins (control production of male and female sex hormones)
• Adrenocorticotrophic hormone or ACTH (controls the adrenal gland and its production of cortisol, DHEA, and other hormones)

When to Contact a Medical Professional

Call your health care provider if your child seems abnormally short for his or her age.

Prevention

Most cases are not preventable.

Review your child's growth chart with your physician after each check-up. If your child's growth rate is dropping or your child's projected adult height is much shorter than an average height of both parents, evaluation by a specialist is recommended.

Alternative Names

Pituitary dwarfism; Acquired growth hormone deficiency; Isolated growth hormone deficiency; Congenital growth hormone deficiency; Panhypopituitarism

References

Parks JS, Felner EI. Hypopituitarism. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics.19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 551.

Update Date: 5/7/2012

Updated by: A.D.A.M. Health Solutions, Ebix. Inc., Editorial Team: David Zieve, MD, MHA, and David R. Eltz. Previously reviewed by Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine (8/2/2011).