This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Hemihypertrophy is a condition in which there is excessive (hyper) growth (trophy) of only one side (hemi) of the body, the right side or the left side. Overgrowth may affect only one part of the body, such as a leg or arm, or several different areas of the body. It may not be apparent at birth, but becomes most noticeable as the child grows. Hemihypertrophy can be isolated or may be part of a genetic syndrome, like Beckwith-Wiedemann syndrome. In most cases, the cause of isolated hemihypertrophy is unknown. In cases where the condition is part of a genetic syndrome, the cause depends on the specific syndrome. Treatment may include surgery to correct the differences in the affected body part(s).
For more information, visit GARD.