Growth hormone deficiency is the most common pituitary hormone deficiency and is accompanied by poor overall growth and short stature.
Other symptoms of growth hormone deficiency depend on the child's age and the cause of the deficiency.
Most often, doctors do not find a cause for growth hormone deficiency, but sometimes it is caused by a congenital disorder or brain tumor.
The diagnosis is based on a physical examination, review of the child's growth charts, and testing that may include x-rays, blood tests, genetic tests, stimulation tests, and imaging tests.
Treatment typically includes hormone replacement therapy.
Hormones are chemical messengers that affect the activity of another part of the body. Growth hormone regulates growth and physical development and is produced by the pituitary gland Overview of the Pituitary Gland The pituitary is a pea-sized gland that is housed within a bony structure (sella turcica) at the base of the brain. The sella turcica protects the pituitary but allows very little room for expansion... read more , which is located at the base of the brain.
Pituitary: The Master Gland
If the pituitary gland does not produce enough growth hormone, abnormally slow growth and short stature with normal proportions can result. Children who are deficient in growth hormone can also be deficient in other pituitary hormones such as thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, and luteinizing hormone (this disorder is called hypopituitarism Hypopituitarism Hypopituitarism is an underactive pituitary gland that results in deficiency of one or more pituitary hormones. Symptoms of hypopituitarism depend on what hormone is deficient and may include... read more ).
Short stature is defined as height below the 3rd percentile for the child’s age (according to standard growth charts Height and Weight Charts for Boys and Girls 2 to 10 Years of Age Physical growth refers to an increase in body size (length or height and weight) and in the size of organs. From birth to about age 1 or 2 years, children grow rapidly. After this rapid infant... read more for age and height). In addition to a deficiency of growth hormone, short stature can occur for other reasons. For example, most children and adolescents who have short stature are short because their families are short, or because their growth spurt came at the late end of the normal range of time for such development. Some children are short because of poor weight gain and poor nutrition or because they have certain chronic illnesses that affect the thyroid, heart, lungs, kidneys, or intestines. Other children have genetic disorders that affect bone growth.
A deficiency in growth hormone production most often has an unknown cause, but about 25% of cases have an identifiable cause, including
Symptoms of growth hormone deficiency depend on various factors such as the child's age and the cause.
Children have poor overall growth rates, usually below 2 inches (5 centimeters) per year, and most have short stature but normal upper and lower body proportions. Some children may have a delay in tooth development or a delay in puberty Delayed Puberty Delayed puberty is defined as absence of the start of sexual maturation at the expected time. Most often, children simply develop later than their peers but ultimately develop normally. Sometimes... read more .
Other abnormalities may be present depending on the cause of the growth hormone deficiency. Newborns with growth hormone deficiency may have low blood sugar (hypoglycemia), jaundice Jaundice in the Newborn Jaundice is a yellow color to the skin and/or eyes caused by an increase in bilirubin in the bloodstream. Bilirubin is a yellow substance formed when hemoglobin (the part of red blood cells... read more (hyperbilirubinemia), or other congenital abnormalities such as a small penis (micropenis) in males or face defects (such as a cleft palate Cleft Lip and Cleft Palate The most common birth defects of the skull and face are cleft lip and cleft palate, affecting about 2 of every 1,000 babies. Cleft lip is a separation of the upper lip, usually just below the... read more ). Children may also have symptoms of other hormone deficiencies such as central hypothyroidism Congenital hypothyroidism Hypothyroidism is decreased production of thyroid hormone. Hypothyroidism in children usually occurs when there is a structural problem with the thyroid gland or the thyroid gland is inflamed... read more .
Growth hormone levels in the blood vary widely and are not as useful as other hormone levels in determining why a child's growth is decreased. Thus, doctors make the diagnosis based on a collection of findings.
First, doctors measure the child's height and weight and plot the measurements on age-specific growth charts Height and Weight Charts for Boys and Girls 2 to 10 Years of Age Physical growth refers to an increase in body size (length or height and weight) and in the size of organs. From birth to about age 1 or 2 years, children grow rapidly. After this rapid infant... read more to determine whether they are growing too slowly. Then they often do x-rays of bones in the hand. Such x-rays can show if the bones are developing normally for the child's age. Children who are simply short have normal bone development for their age. Children who have growth hormone deficiency have delayed bone development. Delayed bone development can also occur in other conditions, such as hypothyroidism Hypothyroidism in Infants and Children Hypothyroidism is decreased production of thyroid hormone. Hypothyroidism in children usually occurs when there is a structural problem with the thyroid gland or the thyroid gland is inflamed... read more and delayed puberty Delayed Puberty Delayed puberty is defined as absence of the start of sexual maturation at the expected time. Most often, children simply develop later than their peers but ultimately develop normally. Sometimes... read more .
It is difficult for doctors to assess growth hormone production because growth hormone production fluctuates throughout the day. As a result, measurement of random growth hormone levels is often not helpful. Instead, doctors do blood tests to measure levels of other substances in the blood that are stimulated by growth hormone. Such substances include insulin-like growth factor 1 and insulin-like growth factor binding protein 3. However, these substances may be affected by other conditions, such as hypothyroidism Diagnosis Hypothyroidism is decreased production of thyroid hormone. Hypothyroidism in children usually occurs when there is a structural problem with the thyroid gland or the thyroid gland is inflamed... read more , celiac disease Celiac Disease Celiac disease is a hereditary intolerance to gluten (a protein found in wheat, barley, and rye) that causes characteristic changes in the lining of the small intestine, resulting in malabsorption... read more , and undernutrition Diagnosis Undernutrition is a deficiency of calories or of one or more essential nutrients. Undernutrition may develop because people cannot obtain or prepare food, have a disorder that makes eating or... read more , so doctors may do tests to rule out these conditions.
Other laboratory tests are done to look for other causes of poor growth (such as thyroid, blood, kidney, inflammatory disorders, and immune disorders). Genetic testing may be done if doctors suspect the child has a specific syndrome (such as Turner syndrome Turner Syndrome Turner syndrome is a sex chromosome abnormality in which girls are born with one of their two X chromosomes partially or completely missing. Turner syndrome is caused by the deletion of part... read more ).
If test results suggest that the child has a pituitary disorder, imaging tests of the brain using magnetic resonance imaging Magnetic Resonance Imaging (MRI) In magnetic resonance imaging (MRI), a strong magnetic field and very high frequency radio waves are used to produce highly detailed images. MRI does not use x-rays and is usually very safe... read more (MRI) may be done to look for structural abnormalities in the pituitary gland and for tumors.
If children have no other cause of poor growth and their growth hormone levels are low, doctors typically do a stimulation test. The stimulation test involves giving drugs that stimulate growth hormone production, then measuring growth hormone levels over several hours.
Children are given injections of synthetic growth hormone. The hormones are given until children reach an acceptable height or until children do not grow more than 1 inch (about 2.5 centimeters) in a year. During the first year of treatment, children may grow up to 4 to 5 inches (10 to 12 centimeters), but individual responses vary. Children do not usually have side effects from growth hormone therapy, although some develop mild swelling of the limbs that usually resolves quickly or infrequently develop more serious side effects such as increased pressure in the brain (idiopathic intracranial hypertension Idiopathic Intracranial Hypertension Idiopathic intracranial hypertension is characterized by increased pressure within the skull (intracranial pressure). What triggers the disorder is unknown. People have daily or near daily headaches... read more or a problem in the upper thigh bone that can show up as knee or hip pain or limping (slipped capital femoral epiphysis Slipped Capital Femoral Epiphysis (SCFE) Slipped capital femoral epiphysis is a slippage or separation of the end of the thighbone (femur) at its growth plate in the hip joint. This disorder may be caused by a weakened growing hip... read more ).
Growth hormone also may be used to increase height in children who are short but have normally functioning pituitary glands, but this use is controversial. Some parents feel that short stature is a disorder, but many doctors do not approve of the use of growth hormone in these children. Regardless of the cause of short stature, growth hormone is effective only if given before the bones stop growing.
If identified, some brain tumors can be removed surgically, but children are at high risk of hypopituitarism because surgery may damage the pituitary. Children who have hypopituitarism are given hormones to replace the ones they are lacking (see treatment of hypopituitarism Treatment Hypopituitarism is an underactive pituitary gland that results in deficiency of one or more pituitary hormones. Symptoms of hypopituitarism depend on what hormone is deficient and may include... read more ).