IDH1

IDH1 or Isocitrate dehydrogenase 1 is an enzyme that in humans is encoded by the IDH1 gene. IDH1 is one of the three isocitrate dehydrogenase isoenzymes, and it is often mutated in certain types of cancer.

Function

IDH1 is an enzyme that catalyzes the oxidative decarboxylation of isocitrate, producing alpha-ketoglutarate (α-KG) and CO2. This is a rate-limiting step in the tricarboxylic acid cycle (TCA cycle or Krebs cycle), which is a key metabolic pathway that unifies carbohydrate, fat, and protein metabolism.

Clinical significance

Mutations in the IDH1 gene are often seen in several types of cancer, including glioma, acute myeloid leukemia (AML), and chondrosarcoma. These mutations result in a new ability of the enzyme to catalyze the NADPH-dependent reduction of α-KG to R(-)-2-hydroxyglutarate (2HG). 2HG is often elevated in patients with an IDH1 mutation, which can be used as a diagnostic marker.

Diagnostic use

The presence of IDH1 mutations can be used as a diagnostic tool in the management of several types of cancer. For example, in gliomas, the presence of an IDH1 mutation is associated with a better prognosis. In AML, IDH1 mutations are associated with an intermediate prognosis and can be targeted with specific therapies.

Therapeutic use

Several drugs that target the mutated form of IDH1 have been developed. These drugs inhibit the mutated IDH1 enzyme, reducing the levels of 2HG and potentially reversing the effects of the mutation.

See also

• Isocitrate dehydrogenase
• IDH2
• Cancer
• Glioma
• Acute myeloid leukemia
• Chondrosarcoma