TBL1XR1 and atypical Rett syndrome: Indeed, a recent crystal structure of the NID bound to the TBL1XR1 subunit, which is shared by NCoR1/2 complexes, showed that four adjacent amino acids that are individually mutated in Rett syndrome (one of which is R306) all make intimate molecular contacts with the WD40 domain of TBL1XR1 (Kruusvee et al. 2017).