2-hydroxyglutarate (oncometabolite)

What it is

2-hydroxyglutarate (specifically D-2-hydroxyglutarate, or 2-HG) is an abnormal substance produced by the mutant forms of the IDH enzyme. It is called an "oncometabolite" because it promotes cancer, and it drives glioma development. Reducing it is the goal of IDH inhibitor drugs.

Understanding 2-hydroxyglutarate (oncometabolite)

Normally, the IDH enzyme performs a step in the cell's energy metabolism. When IDH is mutated, the enzyme instead produces large amounts of 2-hydroxyglutarate, which accumulates in the tumor. This substance interferes with the normal regulation of genes (affecting chemical "marks" on DNA and proteins that control which genes are active), pushing cells toward becoming a tumor. Because 2-hydroxyglutarate is central to how IDH-mutant gliomas develop, it became a target for treatment: IDH inhibitor drugs (such as vorasidenib) block the mutant enzyme and dramatically reduce 2-hydroxyglutarate, which can slow tumor growth. 2-hydroxyglutarate can also sometimes be detected by specialized MRI (spectroscopy). Understanding 2-hydroxyglutarate clarifies the abnormal substance that drives IDH-mutant gliomas and that newer drugs target.

Why it matters

Understanding 2-hydroxyglutarate helps patients and families see how the IDH mutation drives the tumor — by producing this abnormal substance — and why newer IDH inhibitor drugs, which reduce it, can slow tumor growth.