Children's Hospital Colorado

Hemihypertrophy in Children

What is hemihypertrophy?

Hemihypertrophy, also referred to as hemihyperplasia, is a condition in which one side of the body or a part of one side of the body is larger than the other.

Hemihypertrophy is related to several congenital syndromes including Beckwith-Wiedemann syndrome and Russell-Silver syndrome. These syndromes are both congenital, which means they are present at birth, and they are genetic, meaning they are passed down from the parents. If a child has hemihypertrophy and it is not related to a syndrome such as these, it is called "isolated hemihypertrophy."

Hemihypertrophy is an overgrowth disorder, and the asymmetry, or unevenness of the body, can range from mild to severe.

Diagnosing hemihypertrophy as soon as possible is important because it is associated with an increased risk for tumors such as Wilms tumor and hepatoblastoma, a type of solid tumor.

Hemihypertrophy causes

Hemihypertrophy is different from many genetic diseases because the genes that cause the disorder can differ from person to person. Genes are made up of deoxyribonucleic acid (DNA), which are made up of chromosomes. Genes form a kind of blueprint for the body and tell it how to form and function. When a gene is mutated or missing, it affects how the body grows.

Hemihypertrophy in children

Hemihypertrophy can be inherited from a child's parents, although it is not always clear which gene causes the disorder. A mutation on chromosome 11 is often associated with hemihypertrophy when linked to Beckwith-Wiedemann syndrome.