TCF4 and atypical Rett syndrome: De novo partial deletions, translocations, missense, and truncating mutations in TCF4 have also been identified in MMID patients without the typical characteristics of PTHS (8, 9, 10, 11, 12, 13) and one missense mutation in TCF4 has been linked to a Rett-like syndrome (RTT-like) (14).