Editing Epigenetics (section)

===Genomic imprinting===
{{Further|Genomic imprinting}}

Some human disorders are associated with genomic imprinting, a phenomenon in mammals where the father and mother contribute different epigenetic patterns for specific genomic loci in their [[germ cells]].<ref name="pmid17121465">{{cite journal | vauthors = Wood AJ, Oakey RJ | title = Genomic imprinting in mammals: emerging themes and established theories | journal = PLOS Genetics | volume = 2 | issue = 11 | pages = e147 | date = November 2006 | pmid = 17121465 | pmc = 1657038 | doi = 10.1371/journal.pgen.0020147 | doi-access = free }}</ref> The best-known case of imprinting in human disorders is that of [[Angelman syndrome]] and [[Prader–Willi syndrome]] – both can be produced by the same genetic mutation, [[chromosome 15q partial deletion]], and the particular syndrome that will develop depends on whether the mutation is inherited from the child's mother or from their father.<ref name="pmid2564739">{{cite journal | vauthors = Knoll JH, Nicholls RD, Magenis RE, Graham JM, Lalande M, Latt SA | title = Angelman and Prader–Willi syndromes share a common chromosome 15 deletion but differ in parental origin of the deletion | journal = American Journal of Medical Genetics | volume = 32 | issue = 2 | pages = 285–90 | date = February 1989 | pmid = 2564739 | doi = 10.1002/ajmg.1320320235 }}</ref>

In the [[Överkalix study]], paternal (but not maternal) grandsons<ref name="paternal-grandson">A person's paternal grandson is the son of a son of that person; a maternal grandson is the son of a daughter.</ref> of Swedish men who were exposed during preadolescence to famine in the 19th century were less likely to die of cardiovascular disease. If food was plentiful, then [[diabetes]] mortality in the grandchildren increased, suggesting that this was a transgenerational epigenetic inheritance.<ref name="pmid16391557">{{cite journal |vauthors=Pembrey ME, Bygren LO, Kaati G, Edvinsson S, Northstone K, Sjöström M, Golding J |date=February 2006 |title=Sex-specific, male-line transgenerational responses in humans |journal=European Journal of Human Genetics |volume=14 |issue=2 |pages=159–66 |doi=10.1038/sj.ejhg.5201538 |pmid=16391557 |doi-access=free}} [[Robert Winston]] refers to this study in a {{cite web | url = http://www.dundee.ac.uk/externalrelations/events/lectures.html | title = Lecture | archive-url = https://web.archive.org/web/20070523074254/http://www.dundee.ac.uk/externalrelations/events/lectures.html| archive-date = 23 May 2007}}</ref> The opposite effect was observed for females – the paternal (but not maternal) granddaughters of women who experienced famine while in the womb (and therefore while their eggs were being formed) lived shorter lives on average.<ref>{{cite web|url=https://www.pbs.org/wgbh/nova/transcripts/3413_genes.html |title=NOVA &#124; Transcripts &#124; Ghost in Your Genes |publisher=PBS |date=16 October 2007 |access-date=26 July 2012}}</ref>