Dwarfism is a condition of short stature. It is defined by the advocacy group Little People of America (LPA) as an adult height of 4 feet 10 inches or under, as a result of a medical or genetic condition. Although other groups may extend the criteria for certain forms of dwarfism to 5 feet, the average height of an adult with dwarfism is 4 feet. It occurs when an individual person or animal is short in stature resulting from a medical condition caused by slow growth.
Dwarfism can result from myriad medical conditions, each with its own separate symptoms and causes. Extreme shortness in humans with proportional body parts usually has a hormonal cause, such as growth-hormone deficiency, once called pituitary dwarfism. Two disorders, achondroplasia and growth hormone deficiency (also known as pituitary dwarfism), are responsible for the majority of human dwarfism cases The main causes of this disease is due to growth hormone deficiency.
Growth hormone deficiency has no single definite cause. It can be caused by mutations of specific genes, damage to the pituitary gland, Turner's syndrome, poor nutrition, or even stress (leading to psychogenic dwarfism). Laron syndrome or growth hormone insensitivity is another cause. The most recognizable and most common form of dwarfism in humans is achondroplasia, which accounts for 70% of dwarfism cases, occurs in 4 to 15 out of 100,000 live births.