Dwarfism is a medical or genetic condition that usually results in an adult height of 4'10" or shorter, among both men and women, although in some cases a person with a dwarfing condition may be slightly taller than that. The average height of an adult with dwarfism is 4’0, but typical heights range from 2’8 to 4’8.
Common Types of Dwarfism
The most frequently diagnosed cause of short stature is achondroplasia, a genetic condition that results in disproportionately short arms and legs. The average height of adults with achondroplasia is 4'0". Other relatively common genetic conditions that result in disproportionate short stature include spondyloepiphyseal dysplasia congenita (SEDc), diastrophic dysplasia, pseudoachondroplasia, hypochondroplasia, and osteogenesis imperfecta (OI). As one might expect from their names, pseudoachondroplasia and hypochondroplasia are conditions that have been confused with achondroplasia; diastrophic dysplasia occasionally is, too. OI is characterized by fragile bones that fracture easily.
The frequency of occurrence of the most common types of dwarfism (Greenberg Center at Johns Hopkins Medical Center, Lee Kitchens):
Achondroplasia (one per 26,000 to 40,000 births)
SEDc (one per 95,000 births)
Diastrophic dysplasia (one per 110,000 births)
Proportionate dwarfism -- short-stature conditions that result in the arms, legs, trunk, and head being in the same proportion (relative size to one another) as in an average-size person -- is often the result of a hormonal deficiency, and may be treated medically, resulting in an average or near average height. There are not such treatments available for people with disproportionate short stature.
Although achondroplasia accounts for perhaps 70 percent of all cases of dwarfism, there are over 200 diagnosed types, and there are some individuals with dwarfism who never receive a definitive diagnosis and/or have a condition that is unique to themselves or their family.
- There are over 200 distinct types of dwarfism. The most common type is achondroplasia.
- Over 80% of people with dwarfism have average height parents, siblings and children.
- It is very rare to have any type of mental impairment with dwarfism.
- Preferred terminology for someone with dwarfism is "short stature," "having dwarfism," "little person," or "dwarf." The term "midget" is antiquated, and can be perceived by some as a rude slang word.
- People with dwarfism are able to do everything an average-height person can - they can ride bikes, play sports, drive cars, travel, have fulfilling careers and families; they just may need a stool or a simple accommodation.