By Dr Ananya Mandal, MD
The medical term for dwarfism is restricted growth. The condition is typically characterized by a short stature and various other symptoms, depending on the cause of the condition.
Symptoms and causes of dwarfism
Dwarfism is generally defined as an adult height that is below 4 feet 10 inches (147 cm) and the average height among individuals with dwarfism is 4 feet (122 cm).
Over 200 different disorders exist that can cause restricted growth and aside form short stature, symptoms vary widely between individuals. These disorders are generally divided into those that cause two forms of dwarfism; proportionate short stature, which refers to an overall lack of growth and disproportionate short stature, which is the result of abnormal bone growth. The majority of dwarfism cases are of the DSS form and most of those are caused by a condition called achondroplasia.
Disproportionate short stature (DSS)
In DSS, some parts of the body are of normal size or larger than normal, while others are small. In most cases, it is the trunk that is of an average size and the limbs that are short, but the opposite can occur. The head may be large compared with the body size.
Proportionate short stature (PSS)
Here, all parts of the body are small but they are in proportion to each other. Disorders that cause PSS affect overall growth and several bodily symptoms. Usually, the cause of PSS is having small parents. Another cause of PSS is growth hormone deficiency, which is caused by the pituitary gland failing to produce sufficient levels of growth hormone.
Signs of this condition include slow growth rate for age; delayed or absent sexual development and height below the third percentile.
Diagnosis and treatment
A diagnosis of dwarfism is based primarily on measurements of the child’s height, weight and head circumference. Other factors taken into consideration include genetics, family medical history and the results of hormone tests and imaging studies.
Treatment cannot improve stature but is aimed at improving complications of the condition.
Some examples of the surgical procedures used to address abnormal bone growth include:
- The insertion of metal plates in the growth plates of bones
- The straightening of bones and addition of metal plates to hold them in place
- The insertion of rods and staples to correct the spine’s shape
- Limb lengthening, which involves dividing the bone and separating the sections
Growth hormone deficiency
Growth hormone deficiency can be treated by administering injections of synthetic growth hormone. Children usually require daily injections until they reach their maximum height, which is usually an average across the height of their family members. Treatment is also continued to ensure the person matures as normal during adulthood, developing a healthy amount of fat and muscle, for example.
Aside from treatment, people with dwarfism may require support that can improve their quality of life such as the provision of adapted furniture or therapy to help them cope with any anxiety or depression. Promoting independence and helping individuals to develop a good self esteem are important elements in supporting people with dwarfism.
Reviewed by Sally Robertson, BSc
Last Updated: Oct 8, 2014