Dwarfism is a condition characterized by short stature that results from a genetic or medical condition. It is generally defined as an adult height of 4 feet 10 inches (147 centimeters) or less, although some groups extend the criteria for certain forms of dwarfism to 5 feet. The average adult height among people with dwarfism is 4 feet (122 cm) . There are two main categories of dwarfism:
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Disproportionate dwarfism: If body size is disproportionate, some parts of the body are small, and others are of average size or above-average size. Disorders causing disproportionate dwarfism inhibit the development of bones.
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Proportionate dwarfism: The head, trunk, and limbs are all small, but theyre proportionate to each other. These disorders affect overall growth, and many of them result in poor development of one or more body systems. Growth hormone deficiency is a relatively common cause of proportionate dwarfism.
Many different medical conditions can cause dwarfism, and there are over 100 conditions that cause abnormal skeletal growth and dwarfism. Achondroplasia is the most common type of short-limb dwarfism, occurring in around one in 25,000 children with both sexes at equal risk. Other genetic conditions, kidney disease, and problems with metabolism or hormones can also cause dwarfism. Symptoms of dwarfism depend on the underlying cause. For example, disproportionate dwarfism is characterized by either short limbs or a short torso, while proportionate dwarfism is caused by a medical condition that hinders growth and development.
