Acatalasia is an

autosomal recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

peroxisomal disorder Peroxisomal disorders represent a class of medical conditions caused by defects in peroxisome functions. This may be due to defects in single enzymes important for peroxisome function or in peroxins, proteins encoded by ''PEX'' genes that are criti ...

caused by absent or very low levels of the enzyme

catalase Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting t ...

. Catalase breaks down

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

in cells into water and oxygen. Low levels of catalase can cause hydrogen peroxide to build up, causing damage to cells.

Presentation

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

gangrene Gangrene is a type of tissue death caused by a lack of blood supply. Symptoms may include a change in skin color to red or black, numbness, swelling, pain, skin breakdown, and coolness. The feet and hands are most commonly affected. If the ga ...

. Symptoms primarily affect children.

Genetic

Acatalasia is often the result of mutations in both copies of the CAT gene which codes for the enzyme

. There are multiple types of mutation that can cause this condition. Inheriting a single CAT mutation results in hypocatalasia, in which catalase levels are reduced, but still at functional levels.

Diagnosis

This disorder is commonly diagnosed pouring

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

Management

Epidemiology

In parts of Japan, this condition has been found in approximately 1.4% of people. Researchers estimate that the condition occurs in 1 in 20,000 people in Hungary and Switzerland.

History

In 1948, Dr.

Shigeo Takahara Acatalasia is an autosomal recessive peroxisomal disorder caused by absent or very low levels of the enzyme catalase. Catalase breaks down hydrogen peroxide in cells into water and oxygen. Low levels of catalase can cause hydrogen peroxide to b ...

(1908–1994), a

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

otolaryngologist Otorhinolaryngology ( , abbreviated ORL and also known as otolaryngology, otolaryngology–head and neck surgery (ORL–H&N or OHNS), or ear, nose, and throat (ENT)) is a surgical subspeciality within medicine that deals with the surgical a ...

first reported this new disease. He had examined a patient with an

oral ulcer A mouth ulcer (aphtha) is an ulcer that occurs on the mucous membrane of the oral cavity. Mouth ulcers are very common, occurring in association with many diseases and by many different mechanisms, but usually there is no serious underlying cause ...

. He had spread

on the diseased part, but

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

was not generated due to the lack of catalase.

References

External links

{{Peroxisomal disorders Peroxisomal disorders Autosomal recessive disorders Conditions of the mucous membranes