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. Here, PITX2 is linked to Axenfeld-Rieger syndrome.