Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder caused by haploinsufficiency of the TCF4 gene which encodes the transcription factor 4 protein (TCF4) (Amiel et al., 2007; Brockschmidt et al., 2007; Christiane Zweier et al., 2007). This evidence concerns the gene TCF4 and Pitt-Hopkins syndrome.