Animal models of megalin deficiency recapitulate several Donnai-Barrow syndrome symptoms, such as forebrain abnormalities, agenesis of corpus callosum, holoprosencephaly, eye defects, defects in cardiovascular development (Willnow et al., 1996; Kantarci et al., 2007). The gene discussed is LRP2; the disease is Donnai-Barrow syndrome.