The MED12 gene provides an instruction to make a protein known as MED12 which is part of a larger group of proteins known as the Mediator complex. Mediator is involved in turning other genes on and off.
The following conditions have been found to be caused by distinct changes in the MED12 gene:
- FG syndrome: usually due to the same change in MED12 known as p.Arg961Trp. A different change, p.Gly958Glu, was reported in a few individuals with features of FG syndrome.
- Lujan syndrome: the same change in MED12, known as p.Asn1007Ser, causes Lujan syndrome.
- X-linked Ohdo syndrome: multiple different changes (p.Arg1148His, p.Ser1165Pro, p.His1729Asn) in the MED12 gene have been found to cause X-linked Ohdo syndrome.
- Nonsyndromic intellectual disability: individuals with clinical features different from the recognizable syndromes above have been found to have intellectual disability due to distinct changes in the MED12 gene (p.Gln1974His, p.Ala1383Thr, p.Arg815Gln, p.Ile1023Val, p.Ser1967GlnfsTer84).