Dwarfism may be defined as significantly short stature as an adult. There are hundreds of different conditions that can cause dwarfism. The vast majority of people with dwarfism have normal intelligence and can expect to live full life spans. Though people with dwarfism are protected from discrimination under the Americans with Disabilities Act, many do not consider themselves disabled. Most types of dwarfism neither have nor require a cure.

Skeletal dysplasias (conditions of abnormal bone growth) are the most common forms of dwarfism. They are divided into two types: short-limb and short-trunk dysplasias. These conditions affect bone and cartilage growth and result in unusually short stature and body parts (e.g., arms, legs) that are disproportionate in length in comparison to the rest of the body. Achondroplasia is the most common form of dwarfism. People with this type of skeletal dysplasia have a relatively long trunk with short upper arms, thighs, fingers and toes. Many other conditions, including hormonal problems during childhood, can also result in dwarfism.

Many infants and children with dwarfism, particularly those with skeletal dysplasias, do not learn motor skills (e.g., sitting up, walking) as early as other children their age. However, cognitive (mental) delays are not usually present. When a child with dwarfism begins to walk, he or she may have a waddling walk and may be bowlegged or knock-kneed. Spinal problems (e.g., humpback, swayback, scoliosis) may also occur.

Self-esteem and a sense of independence are best established early. It is important to regard dwarfism, especially skeletal dysplasias, as a physiological difference rather than a problem. This outlook is important for both the child and the people with whom the child socializes.

Certain forms of dwarfism are genetic. In some cases, a person with dwarfism has one dwarfism gene, which can be inherited from either parent. However, most children born with dwarfism do not have parents with the condition. Many forms of dwarfism are usually the result of a spontaneous mutation in a single gene in either a sperm or egg cell from average-sized parents. It is not known why this occurs, but it may happen in any pregnancy.

Some forms of dwarfism can be identified prenatally. This may be done through a series of ultrasounds or through karyotypes (tests that allow physicians to evaluate the fetus’s genes). Other cases of dwarfism are discovered immediately after the child is born. Hormonal problems, such as growth hormone deficiency, are frequently the cause of dwarfism that is not discovered until the child is older.

Growth charts are important in the diagnosis of dwarfism. These measure a child’s growth rate and allow it to be compared to those of thousands of children throughout the country. There are special growth charts for children with many conditions that cause dwarfism, including achondroplasia.