MED25Mediator of RNA polymerase II transcription subunit 25 is an enzyme that in humans is encoded by the MED25 gene.Intellectual developmental disorderA homozygous variant in the MED25 gene, leading to an arginine to trypsin substitution, was identified in seven individuals with impaired intellectual development and characteristic facial features. The genetic variant segregated with the disorder and was not found in control populations. This putative homozygous variant arose 218 years ago in this Brazilian family.InteractionsMED25 has been shown to interact with MED4.