{"id":31958,"date":"2019-01-25T01:00:37","date_gmt":"2019-01-24T22:00:37","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=31958"},"modified":"2019-01-25T06:25:30","modified_gmt":"2019-01-25T03:25:30","slug":"cinin-hiv-direncli-bebekleri-tum-dunyayi-gerdi","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2019\/01\/25\/cinin-hiv-direncli-bebekleri-tum-dunyayi-gerdi","title":{"rendered":"\u00c7in\u2019in HIV-diren\u00e7li bebekleri t\u00fcm d\u00fcnyay\u0131 gerdi"},"content":{"rendered":"

\u201cBu \u00e7al\u0131\u015fmada yap\u0131lan etik ihlallerin II. D\u00fcnya Sava\u015f\u0131\u2019ndan bu yana modern t\u0131p tarihinin kay\u0131tlar\u0131na ge\u00e7mi\u015f en korkun\u00e7 \u00f6rneklerden biri oldu\u011funu iddia ediyorum. T\u00fcm d\u00fcnyadan ara\u015ft\u0131rmac\u0131lar\u0131n bu \u00e7al\u0131\u015fmadan utan\u00e7 duymas\u0131 ve ayn\u0131 \u015fekilde bilim camias\u0131n\u0131n bu \u00e7al\u0131\u015fmay\u0131 \u201cpervas\u0131z\u201d olarak nitelendirmesi i\u00e7in her t\u00fcrl\u00fc sebep mevcut.\u201d
\nBu zehir gibi s\u00f6zler Tufts \u00dcniversitesi\u2019nde (ABD) halk sa\u011fl\u0131\u011f\u0131 ve etik konusundaki \u00e7al\u0131\u015fmalar\u0131yla tan\u0131nan Sheldon Krimsky\u2019ye ait; yerden yere vurdu\u011fu \u00e7al\u0131\u015fma ise 2018\u2019in Kas\u0131m ay\u0131 sonunda Hong Kong\u2019da d\u00fczenlenen II. Uluslararas\u0131 \u0130nsan Genomunu D\u00fczenleme Zirvesi\u2019nde, gen d\u00fczenleme tekni\u011fini kullanarak HIV vir\u00fcs\u00fcne diren\u00e7li ilk bebeklerin do\u011fumunu ger\u00e7ekle\u015ftirdi\u011fini a\u00e7\u0131klayan \u00c7inli ara\u015ft\u0131rmac\u0131 He Jiankui\u2019ye… Jiankui 29 Kas\u0131m g\u00fcn\u00fc, Nobel \u00f6d\u00fcll\u00fc David Baltimore\u2019dan, Wisconsin \u00dcniversitesi\u2019nden me\u015fhur biyoetik\u00e7i Alta Charo\u2019ya ve CRISPR\u2019\u0131n yarat\u0131c\u0131lar\u0131ndan Jennifer Doudna\u2019ya kadar gen d\u00fczenleme teknolojisinin en sayg\u0131n ve bilinen isimleri \u00f6n\u00fcnde yapt\u0131\u011f\u0131, \u00e7al\u0131\u015fmas\u0131yla ilgili a\u00e7\u0131klamadan \u00e7ok k\u0131sa bir s\u00fcre sonra kendi \u00fclkesi dahil b\u00fct\u00fcn d\u00fcnyan\u0131n hedef tahtas\u0131na oturdu. \u00d6nce \u00c7in Ulusal Sa\u011fl\u0131k Bakanl\u0131\u011f\u0131\u2019n\u0131n tefti\u015f heyeti Jiankui hakk\u0131nda soru\u015fturma ba\u015flatt\u0131. Ard\u0131ndan ba\u011fl\u0131 oldu\u011fu \u00fcniversite taraf\u0131ndan yaln\u0131z b\u0131rak\u0131ld\u0131; y\u00f6netim Jiankui\u2019nin \u00e7al\u0131\u015fmalar\u0131ndan haberdar olmad\u0131klar\u0131n\u0131, herhangi bir onay s\u00fcrecinin i\u015flemedi\u011fini ve hatta deneyin tepki \u00e7eken kritik a\u015famas\u0131n\u0131n kendi \u00e7at\u0131lar\u0131 alt\u0131nda ger\u00e7ekle\u015ftirilmemi\u015f oldu\u011funu s\u00f6yl\u00fcyordu. Jiankui \u00e7al\u0131\u015fmas\u0131 kapsam\u0131na HIV- kad\u0131n ve HIV+ erkeklerden olu\u015fan sekiz g\u00f6n\u00fcll\u00fc \u00e7ift alm\u0131\u015f, bu ki\u015filerin \u00fcreme h\u00fccrelerinde gen d\u00fczenleme tekni\u011fini uygulay\u0131p d\u00f6llenmi\u015f sa\u011fl\u0131kl\u0131 yumurtay\u0131 anne adaylar\u0131n\u0131n rahmine yerle\u015ftirmi\u015fti. Neticede Jiankui\u2019nin deneyi ilk meyvelerini Nana ve Lulu isimli ikizlerin do\u011fumuyla vermi\u015f ve \u00c7inli ara\u015ft\u0131rmac\u0131 haberi i\u015fte yukar\u0131da bahsedilen zirvede duyurmu\u015ftu. Gel g\u00f6r ki bu haber kimseyi mutlu etmedi! \u00d6yle ki ba\u011fl\u0131 oldu\u011fu \u00fcniversitenin ard\u0131ndan i\u015flemin ger\u00e7ekle\u015ftirildi\u011fi hastane de Jiankui\u2019nin \u00e7al\u0131\u015fmas\u0131ndan haberdar olmad\u0131klar\u0131n\u0131, y\u00f6netimden etik onay al\u0131nmad\u0131\u011f\u0131n\u0131 ileri s\u00fcrd\u00fc. Jiankui\u2019nin elindeki onay formlar\u0131nda yer alan imzalar nereden gelmi\u015f de o ka\u011f\u0131d\u0131n \u00fczerine konmu\u015ftu, a\u00e7\u0131klanamad\u0131\u2026 \u00c7ok ge\u00e7meden Jiankui\u2019nin \u00e7al\u0131\u015fmalar\u0131n\u0131 payla\u015ft\u0131\u011f\u0131 internet sitesi eri\u015fime kapand\u0131. Hatta bu deneyle ilgili olmayan ba\u015fka \u00e7al\u0131\u015fmalar\u0131 hakk\u0131ndaki ba\u015far\u0131lar\u0131ndan s\u00f6z eden haberler de ortadan bir anda kayboldu. \u00c7in Bilimler Akademisi, \u00c7in Genetik\u00e7iler Birli\u011fi ve \u00c7in K\u00f6k H\u00fccre Ara\u015ft\u0131rmalar\u0131 Toplulu\u011fu ortak bir bildiriyle \u00e7al\u0131\u015fmay\u0131 k\u0131nad\u0131klar\u0131n\u0131 bildirdiler. Bat\u0131\u2019n\u0131n a\u00e7\u0131k dahline gerek kalmadan \u00c7in\u2019de yetkili veya uzman konumda kim varsa He Jiankui\u2019nin hakk\u0131ndan fazlas\u0131yla gelmi\u015fti. Sonunda bakanl\u0131k tefti\u015fi de tamamland\u0131 ve ara\u015ft\u0131rmac\u0131n\u0131n, t\u00fcp bebek merkezlerinde \u00fcretilen embriyolar\u0131n ara\u015ft\u0131rmalarda kullan\u0131m\u0131yla ilgili 2003 tarihli (cezai yapt\u0131r\u0131m\u0131 olmayan, yasa niteli\u011fi ta\u015f\u0131mayan) y\u00f6netmeli\u011fe, ayr\u0131ca HIV\u2019li insanlar\u0131n t\u0131bbi yard\u0131mla \u00fcreme y\u00f6ntemlerinden faydalanmalar\u0131n\u0131 yasaklayan d\u00fczenlemelere uymad\u0131\u011f\u0131 (hatta HIV- kad\u0131nlar\u0131 deneye bu sebeple dahil etti\u011fi) ve t\u00fcm bunlar\u0131 \u201cservet ve \u015f\u00f6hret\u201d u\u011fruna yapt\u0131\u011f\u0131 h\u00fckm\u00fcne var\u0131ld\u0131. Ve nihayet He Jiankui\u2019nin pay\u0131na servet ve \u015f\u00f6hret yerine bilimsel kariyerinden ve sayg\u0131nl\u0131\u011f\u0131ndan olmak d\u00fc\u015ft\u00fc: Nature<\/em> dergisinin \u00c7in\u2019in resmi haber kaynaklar\u0131ndan Xinhua\u2019ya dayand\u0131rd\u0131\u011f\u0131 22 Ocak tarihli haberine g\u00f6re Jiankui sonunda Shenzen Bilim ve Teknoloji \u00dcniversitesi\u2019ndeki g\u00f6revinden de oldu. Peki Jiankui tam olarak ne yapt\u0131, nas\u0131l yapt\u0131 ya da yapt\u0131m dedi\u011fi \u015feyi yapabildi mi?<\/p>\n

\"\"
He Jiankui II. Uluslararas\u0131 \u0130nsan Genomunu D\u00fczenleme Zirvesi\u2019ndeki me\u015fhur konu\u015fmas\u0131n\u0131 yaparken. Kaynak: Alex Hoffard\/EPA-EFE\/Shutterstock.<\/figcaption><\/figure>\n

Nana ve Lulu ger\u00e7ek mi?
\n<\/strong>He Jiankui\u2019nin kulland\u0131\u011f\u0131, CRISPR k\u0131saltmas\u0131yla bilinen gen d\u00fczenleme y\u00f6ntemi 2013\u2019ten bu yana Bat\u0131 bilim camias\u0131n\u0131n en g\u00f6zde konusu. Bakterilerin vir\u00fcslere kar\u015f\u0131 \u00fcretti\u011fi bir savunma mekanizmas\u0131n\u0131n, istenen gende istenen dizi de\u011fi\u015fikli\u011fini yapacak bi\u00e7imde d\u00f6n\u00fc\u015ft\u00fcr\u00fclmesi esas\u0131na dayan\u0131yor. \u00dcstelik \u00e7ok etkili, kolay ve ucuz bir \u015fekilde\u2026 \u00d6yle ki art\u0131k CRISPR teknolojisini kullanarak bir \u015feylerin genini d\u00fczenlemeye, d\u00fczeltmeye ya da iyile\u015ftirmeye \u00e7al\u0131\u015fmayan molek\u00fcler biyoloji laboratuvar\u0131 yok gibi. Ticari \u00f6neme sahip bitkiler, tar\u0131m \u00fcr\u00fcnleri, besi hayvanlar\u0131, hastal\u0131k ta\u015f\u0131yan sivrisinekler, \u00e7e\u015fit \u00e7e\u015fit hayvan t\u00fcr\u00fc ve hatta belli bir evrenin alt\u0131ndaki insan embriyolar\u0131 (dolay\u0131s\u0131yla do\u011fum a\u015famas\u0131na getirilmemek \u015fart\u0131yla) d\u00fcnyan\u0131n d\u00f6rt yan\u0131nda bu d\u00fczenlemelerden nasibini al\u0131yor. Ama\u00e7 en basit haliyle bozuk genleri d\u00fczg\u00fcn versiyonlar\u0131yla de\u011fi\u015ftirmek. Jiankui de i\u015fte bu y\u00f6ntemden yararlanarak HIV\u2019nin h\u00fccre i\u00e7ine girerken kulland\u0131\u011f\u0131 bir proteine (CCR5) ait geni d\u00fczenleyip faaliyet d\u0131\u015f\u0131 b\u0131rakm\u0131\u015f; b\u00f6ylece vir\u00fcs\u00fcn kap\u0131 olarak kulland\u0131\u011f\u0131 protein \u00fcretilemeyince ortaya \u00e7\u0131kan bebekler HIV vir\u00fcs\u00fcn\u00fcn etki edemeyece\u011fi HIV-diren\u00e7li bireyler olmu\u015flar. Tabii CRISPR t\u00fcm etkinli\u011fine ra\u011fmen bu kadar sorunsuz bir y\u00f6ntem de\u011fil. Hedeflenen alan\u0131n d\u0131\u015f\u0131nda ger\u00e7ekle\u015fen, niyet edilmemi\u015f d\u00fczenlemeler en b\u00fcy\u00fck sorun. Zaten bilim camias\u0131n\u0131n Jiankui\u2019ye kar\u015f\u0131 \u00e7\u0131karken kulland\u0131\u011f\u0131 en somut gerek\u00e7e de bu. Y\u00f6ntemle ilgili sorunlar tam olarak a\u015f\u0131lmadan yap\u0131lm\u0131\u015f her t\u00fcrl\u00fc uygulama, riskli ve tehlikeli bir m\u00fcdahale olarak g\u00f6r\u00fcl\u00fcyor. Jiankui kendi deney d\u00fczene\u011finde bu ihtimalin ekarte edildi\u011fini ve ikizlerde b\u00f6yle bir sorun olmad\u0131\u011f\u0131n\u0131 s\u00f6yl\u00fcyor. Ancak \u00e7al\u0131\u015fmas\u0131n\u0131 herhangi bir hakemli bilimsel dergide yay\u0131nlayamam\u0131\u015f ve adet oldu\u011fu \u00fczere deneklerle \u00e7ocuklar\u0131n DNA dizilerini eri\u015fime a\u00e7\u0131k DNA dizisi veritabanlar\u0131na y\u00fckleyememi\u015f olmas\u0131, s\u00f6ylediklerinin do\u011frulanmas\u0131 ihtimalini ortadan kald\u0131rd\u0131. Jiankui arzu eden ara\u015ft\u0131rmac\u0131lar\u0131n bizzat laboratuvar\u0131na gelip \u00e7al\u0131\u015fma ko\u015fullar\u0131n\u0131 ve sonu\u00e7lar\u0131n\u0131 inceleyebileceklerini de s\u00f6ylemi\u015fti. Ancak dedi\u011fimiz gibi art\u0131k b\u00f6yle bir laboratuvar da yok. Velhas\u0131l eldeki tek kan\u0131t, Jiankui\u2019nin malum zirvede yapt\u0131\u011f\u0131 konu\u015fma kay\u0131tlar\u0131.
\nAra\u015ft\u0131rmac\u0131lar Nana ve Lulu\u2019nun genomunda CCR5 genlerinin d\u00fczenlenmi\u015f farkl\u0131 farkl\u0131 versiyonlar\u0131n\u0131n bulundu\u011funu s\u00f6yl\u00fcyorlar. Yani Jiankui\u2019nin silip genin faaliyet d\u0131\u015f\u0131 kalmas\u0131n\u0131 sa\u011flayan b\u00f6lge genin farkl\u0131 kopyalar\u0131nda farkl\u0131 uzunluklarda silinmi\u015f. Bu mozaik yap\u0131 CRISPR\u2019\u0131n baz\u0131 h\u00fccrelerde etkili olamamas\u0131ndan ya da etkisini her h\u00fccrede ayn\u0131 bi\u00e7imde g\u00f6sterememesinden kaynaklan\u0131yor olabilir. Jiankui CCR5\u2019i se\u00e7me nedenini, baz\u0131 insanlar\u0131n bu gende 32 harflik do\u011fal bir delesyon (yani harf kayb\u0131) ta\u015f\u0131mas\u0131 ve b\u00f6ylece do\u011fal bir HIV direncine sahip olmalar\u0131yla a\u00e7\u0131klam\u0131\u015ft\u0131. Gel g\u00f6r ki kendi kesti\u011fi b\u00f6lge ile bu 32 harflik b\u00f6lge \u00f6rt\u00fc\u015fm\u00fcyor. \u00dcstelik HIV soylar\u0131n\u0131n baz\u0131lar\u0131 bu genin kodlad\u0131\u011f\u0131 proteini de\u011fil, bir ba\u015fkas\u0131n\u0131 h\u00fccreye giri\u015f kap\u0131s\u0131 olarak kullan\u0131yor. Yani proteini tamamen ortadan kald\u0131rmak da her zaman \u00e7\u00f6z\u00fcm de\u011fil. Fakat t\u00fcm bunlar i\u015fin teknik yanlar\u0131. As\u0131l mesele etik ba\u011flamda kilitleniyor.
\n2018 Kas\u0131m\u2019\u0131ndaki zirvenin amac\u0131 yumurta, sperm ve embriyoda gen d\u00fczenleme i\u015flemlerinin nas\u0131l yap\u0131lmas\u0131 gerekti\u011fi konusunda uluslararas\u0131 bir mutabakata varmakt\u0131. Bu toplant\u0131 t\u00fcr\u00fcn\u00fcn ilk \u00f6rne\u011fi de\u011fil; CRISPR\u2019\u0131n genom d\u00fczenlemek \u00fczere uygulanabilece\u011finin fark\u0131na var\u0131ld\u0131\u011f\u0131 2013\u2019ten beri ayn\u0131 konu\u015fmalar, ayn\u0131 tart\u0131\u015fmalar yap\u0131l\u0131p duruyor. Genel e\u011filim \u00e7al\u0131\u015fmalar\u0131n t\u00fcm d\u00fcnyada e\u015fg\u00fcd\u00fcml\u00fc y\u00fcr\u00fct\u00fclmesi ve olas\u0131 riskler elenmeden klinik uygulamalara, hele de genleri d\u00fczenlenmi\u015f insan embriyosu \u00fcretimine ge\u00e7ilmemesi y\u00f6n\u00fcnde. Ancak d\u00fczenleyici bir mercii kurulabilmi\u015f, denetim konusunda somut ad\u0131mlar at\u0131labilmi\u015f de\u011fil. G\u00f6r\u00fcnen o ki yaz\u0131l\u0131 olsun ya da olmas\u0131n, herhangi bir ara\u015ft\u0131rmac\u0131n\u0131n bu mutabakat\u0131n d\u0131\u015f\u0131na \u00e7\u0131kmas\u0131, Sheldon Krimsky\u2019nin yukar\u0131daki deyimiyle, evet, \u201cpervas\u0131zl\u0131k\u201d. Fakat sadece etik a\u00e7\u0131dan de\u011fil, kendi bilimsel gelece\u011fi ve hatta belki de \u00f6zg\u00fcrl\u00fc\u011f\u00fc a\u00e7\u0131s\u0131ndan da \u00f6yle\u2026<\/p>\n

Kaynaklar:<\/strong><\/p>\n

1) Sheldon Krimsky, \u201cTen ways in which He Jiankui violated ethics\u201d, Nature Biotechnology<\/em>, Cilt 37, s. 19\u201320 (2019).<\/p>\n

2) David Cyranoski, \u201cCRISPR-baby scientist fired by university\u201d, Nature News<\/em>, 22 Ocak 2019.<\/p>\n

3) David Cyranoski & Heidi Ledford, \u201cGenome-edited baby claim provokes international outcry\u201d, Nature News<\/em>, 26 Kas\u0131m 2018.<\/p>\n

4) David Cyranoski, \u201cFirst CRISPR babies: six questions that remain\u201d, Nature News<\/em>, 30 Kas\u0131m 2018.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

\u201cBu \u00e7al\u0131\u015fmada yap\u0131lan etik ihlallerin II. D\u00fcnya Sava\u015f\u0131\u2019ndan bu yana modern t\u0131p tarihinin kay\u0131tlar\u0131na ge\u00e7mi\u015f en korkun\u00e7 \u00f6rneklerden biri oldu\u011funu iddia ediyorum. T\u00fcm d\u00fcnyadan ara\u015ft\u0131rmac\u0131lar\u0131n bu \u00e7al\u0131\u015fmadan utan\u00e7 duymas\u0131 ve ayn\u0131 \u015fekilde bilim camias\u0131n\u0131n bu \u00e7al\u0131\u015fmay\u0131 \u201cpervas\u0131z\u201d olarak nitelendirmesi i\u00e7in her t\u00fcrl\u00fc sebep mevcut.\u201d Bu zehir gibi s\u00f6zler Tufts \u00dcniversitesi\u2019nde (ABD) halk sa\u011fl\u0131\u011f\u0131 ve etik […]<\/p>\n","protected":false},"author":184,"featured_media":31959,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,669,3729],"tags":[1493,4464,4466,4465],"class_list":["post-31958","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","category-etik","category-genetik","tag-crispr","tag-gen-duzenleme","tag-genleri-duzenlenmis-ilk-bebekler","tag-he-jiankui"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/31958","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/users\/184"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=31958"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/31958\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/31959"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=31958"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=31958"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=31958"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}