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. There are two main categories of dwarfism -- disproportionate and proportionate. Disproportionate dwarfism is characterized by an average-size torso and shorter arms and legs or a shortened trunk with longer limbs. In proportionate dwarfism, the body parts are in proportion but shortened.