Plays an important role in the regulation of embryonic development and as signaling molecule in the induction and patterning of the embryonic brain. Required for normal brain development. Interacts with FGFR3 and FGFR4. Preferentially expressed in the embryonic brain. Detected in embryos at E14.5, but not at E10.5 and E19.5. Preferentially expressed in the neuroepithelia of the isthmus and septum of the embryonic brain at E14.5. The disease is caused by variants affecting distinct genetic loci, including the gene represented in this entry. Some patients carrying mutations in FGF17 also have a mutation in another HH-associated gene including FGFR1, HS6ST1 and FLRT3 (PubMed:23643382). Belongs to the heparin-binding growth factors family.