Besides FOXC1, all individuals with this abnormality also had a deletion of the HI-genes TUBB2A (tubulin, beta-2a MIM*615101) and TUBB2B. Corpus callosum abnormalities have also been seen in patients with pathogenic variants in these genes, in combination with a range of other brain malformations [66, 69]. The gene discussed is TUBB2B; the disease is cerebral malformation.