TCF4 and Pitt-Hopkins syndrome: [1650–1 G > A];[=], an established cause of PTHS and a splice acceptor mutation likely causing skipping of exon 18 and encoding p.Ser550Argfs*84 [32], and a 7-year-old girl (UDP_499; PTHS-2) with the mutation NM_001083962.1 (TCF4):c.[1726 C > T];[=] that encodes p.Arg576*.