Semilobar Holoprosencephaly is related to holoprosencephaly 1 and craniosynostosis. An important gene associated with Semilobar Holoprosencephaly is FGF8 (Fibroblast Growth Factor 8), and among its related pathways/superpathways are Nervous system development and Signal Transduction. Affiliated tissues include brain and olfactory bulb, and related phenotypes are failure to thrive and short stature