Heterozygous variants in PAX2 were first identified in 1995 in patients with renal coloboma syndrome (RCS, also known as “papillorenal syndrome”, MIM #120330), which is a rare autosomal dominant disorder characterized by renal hypodysplasia (RHD) and retinal coloboma (HP:0000480)[5]. Here, PAX2 is linked to renal coloboma syndrome.