Editing Sleep (section)

=== Genetics ===
Monozygotic (identical) but not dizygotic (fraternal) twins tend to have similar sleep habits. Neurotransmitters, molecules whose production can be traced to specific genes, are one genetic influence on sleep that can be analyzed. The circadian clock has its own set of genes.<ref>[[#Brown|Brown]], pp. 1138–1102.</ref> Genes which may influence sleep include [[ABCC9]], [[DEC2]], [[Dopamine receptor D2]]<ref name="The Molecular Genetics of Human Sleep">{{cite journal | vauthors = Zhang L, Fu YH | title = The molecular genetics of human sleep | journal = The European Journal of Neuroscience | volume = 51 | issue = 1 | pages = 422–428 | date = January 2020 | pmid = 30144347 | pmc = 6389443 | doi = 10.1111/ejn.14132 }}</ref> and variants near [[PAX8|PAX 8]] and [[VRK2]].<ref name=pmid27494321>{{cite journal | vauthors = Jones SE, Tyrrell J, Wood AR, Beaumont RN, Ruth KS, Tuke MA, Yaghootkar H, Hu Y, Teder-Laving M, Hayward C, Roenneberg T, Wilson JF, Del Greco F, Hicks AA, Shin C, Yun CH, Lee SK, Metspalu A, Byrne EM, Gehrman PR, Tiemeier H, Allebrandt KV, Freathy RM, Murray A, Hinds DA, Frayling TM, Weedon MN | display-authors = 6 | title = Genome-Wide Association Analyses in 128,266 Individuals Identifies New Morningness and Sleep Duration Loci | journal = PLOS Genetics | volume = 12 | issue = 8 | pages = e1006125 | date = August 2016 | pmid = 27494321 | pmc = 4975467 | doi = 10.1371/journal.pgen.1006125 | doi-access = free }}</ref> While the latter have been found in a [[Genome-wide association study|GWAS study]] that primarily detects correlations (but not necessarily causation), other genes have been shown to have a more direct effect. For instance, mice lacking [[Dihydropyrimidine dehydrogenase (NADP+)|dihydropyrimidine dehydrogenase]] (Dpyd) had 78.4 min less sleep during the lights-off period than wild-type mice. Dpyd encodes the rate-limiting [[enzyme]] in the metabolic pathway that catabolizes [[uracil]] and [[thymidine]] to β-[[alanine]], an inhibitory [[neurotransmitter]]. This also supports the role of β-alanine as a neurotransmitter that promotes sleep in mice.<ref>{{cite journal | vauthors = Keenan BT, Galante RJ, Lian J, Zhang L, Guo X, Veatch OJ, Chesler EJ, O'Brien WT, Svenson KL, Churchill GA, Pack AI | display-authors = 6 | title = The dihydropyrimidine dehydrogenase gene contributes to heritable differences in sleep in mice | journal = Current Biology | volume = 31 | issue = 23 | pages = 5238–5248.e7 | date = December 2021 | pmid = 34653361 | pmc = 8665053 | doi = 10.1016/j.cub.2021.09.049 | bibcode = 2021CBio...31E5238K | s2cid = 238754563 }}</ref>

==== Genes for short sleep duration ====
{{Excerpt|Familial natural short sleep}} The genes [[DEC2]], [[ADRB1]], [[NPSR1]] and [[GRM1]] are implicated in enabling short sleep.<ref>{{cite journal |last1=Zheng |first1=Liubin |last2=Zhang |first2=Luoying |title=The molecular mechanism of natural short sleep: A path towards understanding why we need to sleep |journal=Brain Science Advances |date=September 2022 |volume=8 |issue=3 |pages=165–172 |doi=10.26599/BSA.2022.9050003 |s2cid=250363367 |language=en |issn=2096-5958}}</ref>