GLI2 and holoprosencephaly: Variably penetrant variants in GLI2, a zinc-finger transcription factor that mediates SHH transduction, have been described in patients with variable holoprosencephaly phenotypes, including microcephaly, bilateral cleft lip/palate, postaxial polydactyly, optic nerve hypoplasia, and an absent/hypoplastic pituitary with isolated or multiple anterior pituitary hormone deficiencies (8).