The Somatotropin family is a protein family whose titular representative is somatotropin, also known as growth hormone, a hormone that plays an important role in growth control.HGH or somatotropin is a polypeptide secreted by the anterior pituitary. HGH measurement is primarily of interest in the diagnosis and treatment of various forms of abnormal growth hormone secretion. Disorders caused by hyposecretion include dwarfism and unattained growth potential, and hypersecretion is associated with gigantism and acromegaly. Caution must be exercised in the clinical interpretation of growth hormone levels. These vary throughout the day, making it difficult to define a normal range or to judge an individual status based on a single determination.