Pituitary tumors are the most common cause of growth hormone deficiency in children. They can lead to a decrease in the production of growth hormone, which is necessary for normal growth and development.

21-hydroxylase deficiency is the most common type of congenital adrenal hyperplasia. It is an inherited disorder that affects the production of cortisol and aldosterone, two hormones that are essential for life.

Precocious puberty is characterized by the early development of secondary sexual characteristics, such as breast development in girls and testicular enlargement in boys. It can also lead to a growth spurt and acne.

Head injury is the most common cause of diabetes insipidus in children. It can damage the hypothalamus or pituitary gland, which are responsible for the production of antidiuretic hormone (ADH). ADH is necessary for the kidneys to reabsorb water, so a deficiency of ADH can lead to diabetes insipidus.

Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormone. Symptoms of hypothyroidism can include fatigue, weight gain, constipation, and dry skin.

Graves' disease is the most common cause of hyperthyroidism in children. It is an autoimmune disorder that causes the thyroid gland to produce too much thyroid hormone.

Cushing's syndrome is a condition in which the body produces too much cortisol. Symptoms of Cushing's syndrome can include weight gain, buffalo hump, moon face, and striae.

Autoimmune disease is the most common cause of Addison's disease in children. It is a condition in which the body's immune system attacks the adrenal glands, which produce cortisol and aldosterone.

Turner syndrome is a genetic disorder that affects females. Symptoms of Turner syndrome can include short stature, webbed neck, lymphedema, and renal anomalies.

Nondisjunction is the most common cause of Klinefelter syndrome. It is a genetic disorder that occurs when an extra copy of the X chromosome is present in males.

Noonan syndrome is a genetic disorder that affects males and females. Symptoms of Noonan syndrome can include short stature, webbed neck, pectus excavatum, and mental retardation.

Deletion of chromosome 15q11-q13 is the most common cause of Prader-Willi syndrome. It is a genetic disorder that affects males and females. Symptoms of Prader-Willi syndrome can include short stature, obesity, hypotonia, and mental retardation.

Angelman syndrome is a genetic disorder that affects males and females. Symptoms of Angelman syndrome can include a happy demeanor, intellectual disability, ataxia, and seizures.

The cause of Russell-Silver syndrome is unknown. It is a genetic disorder that affects males and females. Symptoms of Russell-Silver syndrome can include short stature, failure to thrive, and feeding difficulties.

Beckwith-Wiedemann syndrome is a genetic disorder that affects males and females. Symptoms of Beckwith-Wiedemann syndrome can include macrosomia, omphalocele, hypoglycemia, and Wilms' tumor.