Growth hormone deficiency - children

Answer 1

Definition

Growth hormone deficiency refers to abnormally short height in childhood due to the lack of growth hormone.

See also: Short stature

Alternative Names

Panhypopituitarism; Pituitary dwarfism; Recombinant human GH (rhGH); Acquired growth hormone deficiency; Congenital growth hormone deficiency; Somatropin

Causes, incidence, and risk factors

Growth hormoneis produced in the pituitary gland, which is located at the base of the brain.

• Different hormones made in the brain tell the pituitary gland how much growth hormone is needed.
• Growth hormone enters the blood and stimulates the liver to produce a hormone called insulin-like growth factor (IGF-1), which plays a key role in childhood growth.

Abnormally short height in childhood (called short stature) may occur if not enough growth hormone is produced.

Most of the time, no single clear cause of growth hormone deficiency is found.

• Growth hormone deficiency may be present at birth (congenital)
• It may also develop after birth, as the result of a brain injury, tumor, or medical condition

Children with physical defects of the face and skull, such as cleft lip or cleft palate, are more likely to have decreased growth hormone levels.

Growth hormone deficiency is usually not passed from parent to child.

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

• Brain radiation treatments for cancer
• Hormonal problems involving the pituitary gland or hypothalamus
• 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.

Signs and tests

A growth chart is used to compare a child's current height, and how fast he or she is growing, to other children of the same age and gender.

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.

Several blood tests are used to help diagnose growth hormone deficiency and its causes:

• GNRH-arginine test
• Growth hormone levels in the blood
• Growth hormone stimulation test
• Insulin tolerance test (ITT, often used to diagnose adults)
• Tests to measure levels of other hormones made by the pituitary gland

Imaging or x-ray tests may include the following:

• Dual energy x-ray absorptiometry (DEXA) scans can also determine bone age.
• 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.
• Measuring growth hormone and binding protein levels (IGF-I and IGFBP-3) will show whether the growth problem is caused by a problem with the pituitary gland.
• MRI of the head can show the hypothalamus and pituitary glands.

Treatment

A child's short stature will often affect self-esteem. Providing emotional support is an important part of treatment. Children may be teased by classmates and playmates. Family, friends, and teachers should emphasize the child's other skills and strengths.

Treatment involves growth hormone injections given at home. Patients may receive growth hormone several times a week or once a day.

Many children gain 4 or more inches over the first year, and 3 or more inches during the next 2 years. Then the growth rate slowly decreases.

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

• Fluid retention
• Muscle and joint aches

Expectations (prognosis)

The earlier the condition is treated, the better the chance that a child will grow to be a near-normal adult height.

Growth hormone replacement therapy does not work for all children.

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:

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

Calling your health care provider

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.

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.

Reiter EO, Rosenfeld RG. Normal and aberrant growth. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier;2008:chap 23.

Cook DM, Yuen KC, Biller BM, Kemp SF, Vance ML; American Association of Clinical Endocrinologists. American Association of Clinical Endocrinologists medical guidelines for clinical practice for growth hormone use in growth hormone-deficient adults and transition patients - 2009 update. Endocr Pract. 2009;15:1-29.

Reviewed By

Review Date: 08/02/2011

Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.