What are the symptoms? Children with GHD are very short, but they have normal body proportion, facial appearance and levels of intelligence. Children may look chubby as growth hormone helps to control the layer of fat under skin. Their facial features may develop slower than usual causing them to appear younger than their age. Hypoglycaemia (low blood sugar) may occur in young children. What are the causes? Most cases of GHD are idiopathic, meaning they are of no known cause. The pituitary gland or the connections to it can be damaged at birth or by severe head injury. Sometimes the connection between the hypothalamus and pituitary gland doesn’t work properly. Underdevelopment of the pituitary gland may occur during fetal development. Midline brain abnormalities that develop in early fetal life may be associated with various pituitary hormone deficiencies. GHD and multiple pituitary hormone deficiency may also occur in association with tumours of the brain or as a secondary complication of the treatment of childhood cancer, usually associated with irradiation of the brain. Genetic abnormalities are now being found to be an important cause of pituitary hormone deficiency. Growth hormone deficiency has been observed to run in families in a small group of children (around 3%). How is it diagnosed? It is difficult to assess growth hormone (GH) levels as these change from hour to hour. Provocation testing involves bringing on a surge of GH using insulin or other substances, such a glucagon. Exercise tests involve using exercise to stimulate GH secretion. Other features of GHD may be useful to help diagnose the condition, including magnetic resonance imaging (MRI) or computed tomography (CT) scans of the pituitary gland. Bone growth may be assessed by taking an X-ray in the left hand and wrist – this establishes how much future growth may be possible. How is it treated? If GH levels are low but not low enough to make a diagnosis of GHD, then growth will be monitored and treatment may not be needed. GHD is treated using a synthetic (man-made) form of GH to stimulate growth, administered as a daily subcutaneous injection (under the skin). Some children and young people with GHD will have low or absent levels of gonadotrophin hormones that cause puberty and sexual development. Additional treatment may be required to manage this. Inheritance patterns and prenatal diagnosis Inheritance patternsThis is dependent the cause of the GHD. Most cases are not inherited. Prenatal diagnosisNone. Is there support? Information and support in the UK for growth hormone deficiency is provided by the Child Growth Foundation (see entry Restricted Growth).