The patients with LCA in families EYE70 and EYE125 carried a known heterozygous missense variant in CRX15 and a novel heterozygous missense variant in IMPDH1, respectively, both of which occurred de novo (Table 1 and Fig. 2), consistent with an ad mode of inheritance. Here, IMPDH1 is linked to Leber congenital amaurosis.