Acatalasemia is a condition characterized by very low levels of an enzyme called catalase. Many people with acatalasemia never have any health problems related to the condition and are diagnosed because they have affected family members.

Mutations in the CAT gene can cause acatalasemia. This gene provides instructions for making the enzyme catalase, which breaks down hydrogen peroxide molecules into oxygen and water. Hydrogen peroxide is produced through chemical reactions within cells. At low levels, it is involved in several chemical signaling pathways, but at high levels it is toxic to cells. If hydrogen peroxide is not broken down by catalase, additional reactions convert it into compounds called reactive oxygen species that can damage DNA, proteins, and cell membranes.

More than 100 cases of acatalasemia have been reported in the medical literature. Researchers estimate that the condition occurs in about 1 in 12,500 people in Japan, 1 in 20,000 people in Hungary, and 1 in 25,000 people in Switzerland. The prevalence of acatalasemia in other populations is unknown.

Acatalasemia has an autosomal recessive pattern of inheritance, which means both copies of the CAT gene in each cell have mutations. When both copies of the gene are altered, the activity of catalase is reduced to less than 10 percent of normal.

Published Date: September 01, 2014Published By: National Institutes of Health