Acatalasia is an autosomal recessive peroxisomal disorder caused by absent or very low levels of the enzyme catalase.

The disorder is relatively benign, although it causes an increased incidence of oral ulcers, and can under rare circumstances lead to gangrene.

[4] Acatalasia is often the result of mutations in both copies of the CAT gene which codes for the enzyme catalase.

Instead of a very bubbling reaction, blood turns brown-colored, which means the patient suffers from acatalasia.

He had spread hydrogen peroxide on the diseased part, but oxygen was not generated due to the lack of catalase.