Providing accurate diagnosis of growth disorders
Growth disorders affect thousands of people each year. A person may be diagnosed as a child or as an adult. There are different types of growth disorders, many caused by imbalances in different types of hormones.1
Growth Hormone Deficiency
Growth hormone deficiency means the pituitary gland does not make enough growth hormone. Most of the time, the cause of growth hormone deficiency is unknown. It may be present at birth or develop as a result of an injury or medical condition. Severe brain injury may also cause growth hormone deficiency. Slow growth may first be noticed in infancy and continue through childhood. Although uncommon, growth hormone deficiency may also be diagnosed in adults. Possible causes include tumors involving the pituitary gland or hypothalamus, or brain radiation treatments for cancer.2
Gigantism–Excessive action of IGF-I while epiphyseal growth plates are open causes gigantism, which occurs very rarely3. Children and adolescents with gigantism stand > 2 standard deviations above the mean height for their gender and age.
Acromegaly–Also caused by hypersecretion of IGF-I, acromegaly is the most common disorder of GH excess4. In contrast to gigantism, it occurs in adolescence and adults after their epiphyseal growth plates have fused. The name acromegaly comes from the Greek words for “extremities”(acro) and “great”(megaly), because one of the most common symptoms of this condition is abnormal growth of the hands and feet.
The symptoms of acromegaly can vary and develop gradually over time; therefore, a diagnosis of this condition may be difficult. Early detection is a goal in the management of acromegaly because the pathologic effects of increased growth hormone (GH) production are progressive.5 IGF-I provides the most sensitive lab test for the diagnosis of acromegaly.6
Kuhnel, W. Growth Diagnostics: Clinical Relevance of GH, IGF-I and IGFBP-3. Los Angeles (CA), Diagnostics Products Corporation (now Siemens Healthcare Diagnostics), Technical Report ZB223-B, 2004.
Ferry, RJ. Giantism and Acromegaly. eMedicine Specialties (Internet): 2010 July. http://emedicine.medscape.com/article/925446-overview