TCF4 and Pitt-Hopkins syndrome: Consistent with previous observations, we observed lower alpha diversity in both PTHS and ASD individuals (PTHS versus AGP ASD, U = 3,668 and P = 0.013; PTHS versus AGP non-ASD, U = 11,372 and P = 0.001; AGP ASD versus AGP non-ASD, U = 124,957 and P = 0.039 [by a Mann U test]).