{"id":200,"date":"2007-04-02T21:33:54","date_gmt":"2007-04-03T04:33:54","guid":{"rendered":"http:\/\/www.laurenwood.org\/anyway\/archives\/2007\/04\/02\/twins-and-genetics\/"},"modified":"2007-04-02T22:05:00","modified_gmt":"2007-04-03T05:05:00","slug":"twins-and-genetics","status":"publish","type":"post","link":"https:\/\/www.laurenwood.org\/anyway\/2007\/04\/twins-and-genetics\/","title":{"rendered":"Twins and Genetics"},"content":{"rendered":"

Mod\u00adern genet\u00adics some\u00adtimes has a bit of a \u201cbelieve it or not\u201d feel\u00ading to it, things are repor\u00adted that sound like they come out of Greek myth\u00ado\u00adlogy. One of the recent news items on the BBC<\/span> had that feel\u00ading for me, where they write about semi-identic\u00adal twins<\/a>. These babies, who come from one egg fer\u00adtil\u00adized by two sperm, have the same mater\u00adnal genet\u00adic mater\u00adi\u00adal and each has some of the paternal genet\u00adic mater\u00adi\u00adal from each sperm. So they\u2019re both chi\u00admer\u00adas, and one is also a herm\u00adaph\u00adrod\u00adite. Search\u00ading through the web for inform\u00ada\u00adtion about soci\u00adety\u2019s treat\u00adment of herm\u00adaph\u00adrod\u00adites through the ages is a good way of spend\u00ading a lot of time read\u00ading inter\u00adest\u00ading art\u00adicles; vari\u00adous cul\u00adtures and soci\u00adet\u00adies have differed greatly in how they treated these people. But I digress. <\/p>\n

In myth\u00ado\u00adlogy chi\u00admer\u00adas are those beasts that are partly one anim\u00adal or mon\u00adster, and partly anoth\u00ader. In the mod\u00adern med\u00adic\u00adal usage of the term, a chi\u00admera has two sets of genet\u00adic mater\u00adi\u00adal, so a DNA<\/span> test taken from one part of the body will give a dif\u00adfer\u00adent res\u00adult to a DNA<\/span> test taken from some oth\u00ader part of the body. Some people with eyes of dif\u00adfer\u00adent col\u00adours are chi\u00admer\u00adas, for example, the dif\u00adfer\u00adent col\u00adours com\u00ading from the dif\u00adfer\u00ading genet\u00adic material.<\/p>\n

Anoth\u00ader genet\u00adic\u00adally inter\u00adest\u00ading con\u00addi\u00adtion that involves twins is the van\u00adish\u00ading twin syn\u00addrome<\/a>, where one twin absorbs all the genet\u00adic mater\u00adi\u00adal of the oth\u00ader, some\u00adtimes lead\u00ading to a chi\u00admera. The per\u00adson, if born before early ultra\u00adsounds were com\u00admon, prob\u00adably won\u2019t even know that he or she star\u00adted off as one of twins. There was a well-known case of a moth\u00ader who could only accept a kid\u00adney trans\u00adplant from one of her three sons because the oth\u00ader two had genet\u00adic mater\u00adi\u00adal from the van\u00adished twin rather than the moth\u00ader who gave birth to them (see the above link or this one<\/a> for more details).<\/p>\n

These things give rise to some inter\u00adest\u00ading issues, such as what about DNA<\/span> test\u00ading? If one per\u00adson can have the DNA<\/span> of two people, with one set of DNA<\/span> in some tis\u00adsues, and the oth\u00ader set in oth\u00ader tis\u00adsues, DNA<\/span> test\u00ading becomes prob\u00adlem\u00adat\u00adic. Cur\u00adrently there\u2019s no way of know\u00ading the real pro\u00adpor\u00adtion of van\u00adished twins, since there is only sel\u00addom a reas\u00adon to test any giv\u00aden per\u00adson thor\u00adoughly enough to find out (one example being need\u00ading to prove par\u00adent\u00adage of chil\u00addren, as in the rel\u00adat\u00adively recent Lydia Fairchild case<\/a>). Chi\u00admer\u00adas can have two blood types as well, mak\u00ading them ideal blood recip\u00adi\u00adents, but less than ideal blood donors. That\u2019s anoth\u00ader way people may find out, I guess, when they get their blood type tested, but again it\u2019s hard to know what pro\u00adpor\u00adtion of chi\u00admer\u00adas have two blood types.<\/p>\n

I hope the par\u00adents of those babies (now tod\u00addlers) suc\u00adceed in keep\u00ading their names and oth\u00ader inform\u00ada\u00adtion private. The interest in their unusu\u00adal genet\u00adic make-up could badly affect their lives if the par\u00adents aren\u2019t strong enough to with\u00adstand pres\u00adsure from the press, or sci\u00adent\u00adists, or the curi\u00adous pub\u00adlic. I also hope they\u2019re treated with com\u00adpas\u00adsion and empathy as they grow older, rather than intrus\u00adive nosiness.<\/p>\n","protected":false},"excerpt":{"rendered":"

Mod\u00adern genet\u00adics some\u00adtimes has a bit of a \u201cbelieve it or not\u201d feel\u00ading to it, things are repor\u00adted that sound like they come out of Greek myth\u00ado\u00adlogy. One of the recent news items on the BBC<\/span> had that feel\u00ading for me, where they write about semi-identic\u00adal twins. These babies, who come from one egg fer\u00adtil\u00adized \u2026 Con\u00adtin\u00adue read\u00ading \u201cTwins and Genetics\u201d<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"wp_typography_post_enhancements_disabled":false,"activitypub_content_warning":"","activitypub_content_visibility":"","activitypub_max_image_attachments":3,"activitypub_interaction_policy_quote":"","activitypub_status":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-200","post","type-post","status-publish","format-standard","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/posts\/200","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/comments?post=200"}],"version-history":[{"count":0,"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/posts\/200\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/media?parent=200"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/categories?post=200"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laurenwood.org\/anyway\/wp-json\/wp\/v2\/tags?post=200"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}