Definition of Growth hormone deficiency:

Growth hormone deficiency involves abnormally short stature with normal body proportions. Growth hormone deficiency may be congenital (present at birth) or acquired (the result of an injury or medical condition).

Causes, incidence, and risk factors:

An abnormally short height in childhood may occur if the pituitary gland does not produce enough growth hormone. Most of the time, no underlying cause is found, but it can be caused by absence of the pituitary gland or severe brain injury.

Growth retardation may become first be noticed in infancy and continue throughout childhood. The child's "growth curve," which is usually plotted on a standardized growth chart by the pediatrician, may range from flat (no growth) to very shallow (minimal growth). Normal puberty may or may not occur, depending on how well the pituitary gland can produce adequate hormone levels other than growth hormone.

Growth hormone deficiency may be associated 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)
• ACTH or adrenocorticotrophic hormone (controls the adrenal gland and its production of cortisol, DHEA, and other hormones)

Physical defects of the face and skull can also be associated with pituitary gland or pituitary function abnormalities. A small percentage of infants with cleft lip and cleft palate have decreased growth hormone levels.

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

• Hormonal problems involving the pituitary gland or the hypothalamus
• Receiving brain radiation treatments for cancer
• Severe head injury