Editing 1999 in science (section)

==Physiology and medicine==
* April 16 – [[Russell Foster]] and his team at [[Imperial College London]] publish their discovery of the non-[[Rod cell|rod]], non-[[Cone cell|cone]], [[intrinsically photosensitive retinal ganglion cell]]s (ipRGCs) in the mammalian eye which provide input to the [[circadian rhythm]] system.<ref>{{Cite journal|last1=Lucas|first1=R. J.|last2=Freedman|first2=M. S.|last3=Muñoz|first3=M.|last4=Garcia-Fernández|first4=J. M.|last5=Foster|first5=R. G.|date=1999-04-16|title=Regulation of the mammalian pineal by non-rod, non-cone, ocular photoreceptors|url=https://www.science.org/doi/10.1126/science.284.5413.505|journal=[[Science (journal)|Science]]|volume=284|issue=5413|pages=505–507|issn=0036-8075|pmid=10205062|doi=10.1126/science.284.5413.505|bibcode=1999Sci...284..505L|url-access=subscription}}</ref>
* October – [[Huda Zoghbi]] demonstrates that [[Rett syndrome]] is caused by mutations in the gene [[MECP2]].<ref>{{cite journal|doi=10.1038/13810|title=Rett syndrome is caused by mutations in X-linked MECP2, encoding methyl-CpG-binding protein 2|year=1999|last1=Amir|first1=Ruthie E.|last2=Van den Veyver|first2=Ignatia|last3=Wan|first3=Mimi|last4=Tran|first4=Charles|last5=Francke|first5=Uta|last6=Zoghbi|first6=Huda Y.|journal=[[Nature Genetics]]|volume=23|issue=2|pages=185–8|pmid=10508514|s2cid=3350350|url=https://www.nature.com/articles/ng1099_185|url-access=subscription}}</ref>