Most mutations that cause<unk>  can be found in the MED12 gene. However, mutations have also been found in FMR1, FLNA, UPF3B, CASK, MECP2 and ATRX genes. Mutations on these different genes lead to the different types of<unk> , all with similar characteristics. The<unk> S8 type mutation is the most common of the types, and is found in the MED12 gene. Known types and affected genes include: Type OMIM Gene Locus<unk> S1 MED12 Xq13<unk> S2 FLNA Xq28<unk> S3<unk> S3 Xp22.3<unk> S4 CASK Xp11.4-p11.3<unk> S5<unk> S5 Xq22.3 MED12 gene The MED12 gene codes for the mediator complex subunit 12 protein. The mediator complex is composed of around 25 different proteins that all help with the regulation of gene activity. This mediator complex regulates gene expression by bridging interaction between RNA polymerase II and gene-specific regulating proteins such as transcription factors, repressor proteins, activator proteins, etc. Changes to this complex and the proteins associated can have a severe impact on the production of new proteins. The MED12 gene is also thought to be highly linked to neuron development as well as high usage in the cells signal transduction pathway. This explains the slowed intellectual development individuals with<unk>  have.
FG syndrome
Gitelman syndrome
Mungan syndrome
Muir–Torre syndrome
Sly syndrome
Perlman syndrome
MORM syndrome
Angelman syndrome