The second individual, presenting with microphthalmia, carries an ~ 113.5 kb homozygous deletion 19.38 kb upstream of MAB21L2. Modelling of the deletion results in transient small lens and coloboma as well as midbrain anomalies in zebrafish, and microphthalmia and coloboma in Xenopus tropicalis. This evidence concerns the gene MAB21L2 and microphthalmia.