PHOX2A and congenital fibrosis of the extraocular muscles: CFEOM is genetically heterogeneous and can be further classified into several subtypes, namely CFEOM1A, CFEOM1B, CFEOM2, CFEOM3A, CFEOM3B, CFEOM3C, Tukel syndrome, and CFEOM3 with polymicrogyria [2].