This intronless gene encodes a member of the basic helix-loop-helix family of transcription factors, with similarity to Drosophila atonal gene that controls photoreceptor development. Studies in mice suggest that this gene plays a central role in retinal ganglion cell and optic nerve formation. Mutations in this gene are associated with nonsyndromic congenital retinal nonattachment. [provided by RefSeq, Dec 2011].