PITX2 and Axenfeld-Rieger syndrome: Mutations in human PITX2 or the forkhead box transcription factor C1 (FOXC1; 6p25, RefSeq NM 001453.2, MIM# 601090) underlie the autosomal dominant disorder called Axenfeld-Rieger syndrome (ARS; MIM# 602482) [2–5].