FOXC2 and Axenfeld-Rieger syndrome: Heterozygous FOXC2 mutations do not produce the malformations observed in patients with FOXC1/PITX2-associated ARS,46,47 but they result in ocular anterior segment anomalies such as iris hypoplasia, pupil displacement, and decreased anterior segment size,46 which are milder than those caused by FOXC1 mutations.