Speci\u00e1ln\u00ed vy\u0161et\u0159en\u00ed m\u016f\u017ee podstoupit embryo vznikl\u00e9 na klinice pro um\u011bl\u00e9 oplodn\u011bn\u00ed je\u0161t\u011b p\u0159ed zaveden\u00edm do mat\u010diny d\u011blohy. Posta\u010d\u00ed jedna bu\u0148ka.<\/p>\n
\u010cast\u00e9 spont\u00e1nn\u00ed potraty i po p\u0159irozen\u00e9m ot\u011bhotn\u011bn\u00ed, n\u011bkolik ne\u00fasp\u011b\u0161n\u00fdch cykl\u016f um\u011bl\u00e9ho oplodn\u011bn\u00ed nebo v\u00fdskyt z\u00e1va\u017en\u00e9ho genetick\u00e9ho posti\u017een\u00ed v rodin\u011b, to v\u0161echno jsou d\u016fvody k proveden\u00ed preimplanta\u010dn\u00edho genetick\u00e9ho vy\u0161et\u0159en\u00ed embry\u00ed. To se ve sv\u011bt\u011b d\u011bl\u00e1 od konce devades\u00e1t\u00fdch let 20. stolet\u00ed a jeho v\u00fdznam roste i u n\u00e1s.
\n„Preimplanta\u010dn\u00ed genetick\u00e1 diagnostika (PGD) umo\u017e\u0148uje vybrat zdrav\u00e9 embryo bez konkr\u00e9tn\u00ed genetick\u00e9 z\u00e1t\u011b\u017ee,“ vysv\u011btluje Sylvie Hlav\u00e1\u010dov\u00e1, embryolo\u017eka ze zl\u00ednsk\u00e9ho institutu reproduk\u010dn\u00ed medic\u00edny Unica. Jde o zp\u016fsob, jak otestovat embryo je\u0161t\u011b p\u0159edt\u00edm, ne\u017e je v\u016fbec implantov\u00e1no do mat\u010diny d\u011blohy, a tedy z\u00e1rove\u0148 mo\u017enost, jak vybrat takov\u00e9, kter\u00e9 neponese konkr\u00e9tn\u00ed genetickou z\u00e1t\u011b\u017e.
\n„Vy\u0161et\u0159en\u00ed spo\u010d\u00edv\u00e1 v odb\u011bru jedn\u00e9 nebo n\u011bkolika bun\u011bk z embrya a jejich genetick\u00e9m vy\u0161et\u0159en\u00ed. Vyu\u017e\u00edv\u00e1 skute\u010dnosti, \u017ee ka\u017ed\u00e1 bu\u0148ka embrya by m\u011bla obsahovat stejn\u00e9 genov\u00e9 vybaven\u00ed a \u017ee p\u0159i v\u00fdvoji embrya nejsou jednotliv\u00e9 bu\u0148ky je\u0161t\u011b specializov\u00e1ny, a tak odebr\u00e1n\u00ed bun\u011bk neovlivn\u00ed dal\u0161\u00ed v\u00fdvoj embrya,“ popisuje princip Monika Koudov\u00e1, l\u00e9ka\u0159sk\u00e1 geneti\u010dka a vedouc\u00ed genetick\u00e9ho programu pra\u017esk\u00e9ho centra Gennet.
\nTato diagnostika se prov\u00e1d\u00ed p\u0159edev\u0161\u00edm u p\u00e1r\u016f, kter\u00e9 trp\u00ed genetickou chorobou, v jejich\u017e rodinn\u00e9 anamn\u00e9ze se vyskytuje genetick\u00e9 zat\u00ed\u017een\u00ed, p\u0159\u00edpadn\u011b se jim ji\u017e narodilo posti\u017een\u00e9 d\u00edt\u011b.
\n„Pro pacienty s genetick\u00fdmi vadami nebo nositele gen\u016f vrozen\u00fdch vad je PGD \u010dasto jedinou \u0161anc\u00ed, jak porodit zdrav\u00e9 d\u00edt\u011b. Je t\u0159eba tak\u00e9 dodat, \u017ee nezaru\u010duje, \u017ee se p\u00e1ru narod\u00ed naprosto zdrav\u00e9 d\u00edt\u011b, ale zabr\u00e1n\u00ed p\u0159enosu konkr\u00e9tn\u00ed genetick\u00e9 z\u00e1t\u011b\u017ee. Co\u017e je i jej\u00edm hlavn\u00edm c\u00edlem,“ dod\u00e1v\u00e1 embryolo\u017eka. P\u0159edpokladem pro vy\u0161et\u0159en\u00ed je, \u017ee je konkr\u00e9tn\u00ed choroba „testovateln\u00e1“ na genetick\u00e9 \u00farovni, tedy v rodin\u011b je zn\u00e1m\u00e1 specifick\u00e1 mutace, kter\u00e1 je za onemocn\u011bn\u00ed zodpov\u011bdn\u00e1.
\nNap\u0159\u00edklad u rodi\u010d\u016f, kte\u0159\u00ed nesou genetickou mutaci pro cystickou fibr\u00f3zu, je riziko, \u017ee jejich d\u00edt\u011b onemocn\u00ed, 25 procent. U nositel\u016f mutace pro Huntingtonovu choreu, kter\u00e1 vede k poruch\u00e1m motoriky, zm\u011bn\u011b osobnosti, demenci a n\u00e1sledn\u011b smrti, je riziko onemocn\u011bn\u00ed jejich d\u00edt\u011bte 50 procent.
\nProveden\u00ed genetick\u00e9ho vy\u0161et\u0159en\u00ed je\u0161t\u011b p\u0159ed zaveden\u00edm embrya do d\u011blohy m\u00e1 v\u00fdznam tak\u00e9 tehdy, pokud je \u017eena nositelka vlohy pro chorobu v\u00e1zanou na chromozom X s rizikem onemocn\u011bn\u00ed chlapc\u016f, co\u017e je t\u0159eba hemofilie nebo Duchennova svalov\u00e1 dystrofie, kdy postupn\u011b doch\u00e1z\u00ed k ochabov\u00e1n\u00ed sval\u016f, kter\u00e9 \u010dlov\u011bka upout\u00e1 na invalidn\u00ed voz\u00edk a nakonec zp\u016fsob\u00ed smrt. V t\u011bchto p\u0159\u00edpadech si p\u00e1rymohou zvolit pohlav\u00ed d\u00edt\u011bte, co\u017e jinak ze z\u00e1kona nelze.<\/p>\n
Lep\u0161\u00ed \u0161ance na \u00fasp\u011b\u0161n\u00e9 t\u011bhotenstv\u00ed<\/p>\n
D\u016fvodem pro proveden\u00ed speci\u00e1ln\u00edch genetick\u00fdch vy\u0161et\u0159en\u00ed tak\u00e9 m\u016f\u017ee b\u00fdt to, \u017ee nen\u00ed z\u0159ejm\u00e9, pro\u010d \u017eena opakovan\u011b potr\u00e1c\u00ed, i kdy\u017e je schopna spont\u00e1nn\u011b ot\u011bhotn\u011bt, nebo pro\u010d jsou cykly um\u011bl\u00e9ho oplodn\u011bn\u00ed opakovan\u011b ne\u00fasp\u011b\u0161n\u00e9. Pro tyto p\u00e1ry je ur\u010den preimplanta\u010dn\u00ed genetick\u00fd screening (PGS), jeho\u017e c\u00edlem je sn\u00ed\u017eit riziko p\u0159enosu embrya posti\u017een\u00e9ho z\u00e1va\u017enou chromozomovou vadou.
\n„Mnoho cykl\u016f um\u011bl\u00e9ho oplodn\u011bn\u00ed m\u016f\u017ee skon\u010dit zklam\u00e1n\u00edm z ne\u00fasp\u011b\u0161n\u00e9ho zahn\u00edzd\u011bn\u00ed embrya a jednou z p\u0159\u00ed\u010din m\u016f\u017ee b\u00fdt porucha u embrya, kdy jeden chromozom chyb\u00ed nebo naopak p\u0159eb\u00fdv\u00e1,“ vysv\u011btluje geneti\u010dka Koudov\u00e1. Zat\u00edmco n\u011bkter\u00e1 takto po\u0161kozen\u00e1 embrya se mohou vyv\u00edjet a\u017e do porodu, jako nap\u0159\u00edklad u Downova syndromu, v\u011bt\u0161ina takov\u00fdch t\u011bhotenstv\u00ed kon\u010d\u00ed spont\u00e1nn\u00edm potratem. S rostouc\u00edm v\u011bkem \u017eeny se toto riziko zvy\u0161uje. „Genetick\u00fd screening tak zvy\u0161uje \u00fasp\u011b\u0161nost implantace embrya a z\u00e1rove\u0148 sni\u017euje riziko potratu v d\u016fsledku abnorm\u00e1ln\u00edho v\u00fdvoje z\u00e1rodku nebo plodu,“ dod\u00e1v\u00e1 l\u00e9ka\u0159ka.
\nPodle doporu\u010den\u00ed Spole\u010dnosti l\u00e9ka\u0159sk\u00e9 genetiky \u010cesk\u00e9 l\u00e9ka\u0159sk\u00e9 spole\u010dnosti J. E. Purkyn\u011b m\u00e1 b\u00fdt prenat\u00e1ln\u00ed genetick\u00fd screening indikov\u00e1n nap\u0159\u00edklad u \u017een nad 35 let, v p\u0159\u00edpad\u011b opakovan\u00fdch spont\u00e1nn\u00ed potrat\u016f nebo ne\u00fasp\u011b\u0161n\u00fdch cykl\u016f um\u011bl\u00e9ho oplodn\u011bn\u00ed. Nejde tedy o vy\u0161et\u0159en\u00ed „na p\u0159\u00e1n\u00ed“, ale prov\u00e1d\u011bn\u00e9 pouze tehdy, kdy\u017e je doporu\u010d\u00ed l\u00e9ka\u0159sk\u00fd genetik po konzultaci s p\u00e1rem a podeps\u00e1n\u00ed informovan\u00e9ho souhlasu.
\nD\u00edky informac\u00edm z\u00edskan\u00fdm p\u0159i genetick\u00fdch vy\u0161et\u0159en\u00edch z\u00e1rodk\u016f je mo\u017en\u00e9 sn\u00ed\u017eit po\u010det zav\u00e1d\u011bn\u00ed embry\u00ed do d\u011blohy matky a po\u010det cykl\u016f um\u011bl\u00e9ho oplodn\u011bn\u00ed, kter\u00e9 vedou k narozen\u00ed zdrav\u00e9ho d\u00edt\u011bte. Tak\u00e9 lze zjistit p\u0159\u00ed\u010dinu opakovan\u00fdch ne\u00fasp\u011bch\u016f um\u011bl\u00e9ho oplodn\u011bn\u00ed a l\u00e9pe se rozhodnout, co d\u00e1l. Uva\u017eovat se pak nap\u0159\u00edklad d\u00e1 o pou\u017eit\u00ed darovan\u00fdch spermi\u00ed a vaj\u00ed\u010dek nebo p\u0159\u00edmo embry\u00ed.<\/p>\n
Pravd\u011bpodobnost, ne jistota<\/p>\n
A\u010dkoliv jsou sou\u010dasn\u00e9 mo\u017enosti l\u00e9ka\u0159sk\u00e9 genetiky ve srovn\u00e1n\u00ed s minulost\u00ed obrovsk\u00e9, neznamen\u00e1 to, \u017ee je mo\u017en\u00e9 a eticky spr\u00e1vn\u00e9 „vyrobit“ stoprocentn\u011b zdrav\u00e9 d\u00edt\u011b.
\nSmyslem pr\u00e1ce l\u00e9ka\u0159\u016f, genetik\u016f a embryolog\u016f je d\u00e1t \u0161anci na d\u00edt\u011b i p\u00e1r\u016fm, kter\u00e9 si s sebou nesou genetickou z\u00e1t\u011b\u017e nebo se jim po\u010det\u00ed opakovan\u011b neda\u0159\u00ed. Lep\u0161\u00ed \u0161ance ale neznamen\u00e1 jistotu.
\n„Preimplanta\u010dn\u00ed diagnostika v sob\u011b zahrnuje obt\u00ed\u017en\u00e9 rozhodov\u00e1n\u00ed: kter\u00e9 z embry\u00ed se implantuje a kter\u00e9 se na z\u00e1klad\u011b medic\u00ednsk\u00e9ho hodnocen\u00ed rizik vy\u0159ad\u00ed. O tom, jestli je dob\u0159e tuto metodu pou\u017e\u00edt, se mus\u00ed rozhodovat pacienti sami,“ p\u0159ipom\u00edn\u00e1 Anna Arellanesov\u00e1, p\u0159edsedkyn\u011b \u010cesk\u00e9 asociace pro vz\u00e1cn\u00e1 onemocn\u011bn\u00ed.<\/p>\n
—<\/p>\n
Preimplanta\u010dn\u00ed genetick\u00e1 diagnostika Rodi\u010d\u016fm, kte\u0159\u00ed maj\u00ed v rodin\u011b vy\u0161\u0161\u00ed riziko d\u011bdi\u010dn\u00fdch chorob, umo\u017e\u0148uje vybrat zdrav\u00e9 embryo vytvo\u0159en\u00e9 na klinice pro um\u011bl\u00e9 oplodn\u011bn\u00ed a to implantovat do d\u011blohy matky, tak\u017ee se zvy\u0161uje \u0161ance na narozen\u00ed zdrav\u00e9ho d\u00edt\u011bte.<\/p>\n
1. Z p\u011btidenn\u00edho embrya, kter\u00e9 se skl\u00e1d\u00e1 z asi stovky bun\u011bk, se jich n\u011bkolik odebere.<\/p>\n
2. P\u0159i genetick\u00e9m testu se v laborato\u0159i zkontroluje v\u0161ech 23 p\u00e1r\u016f chromozom\u016f v j\u00e1dru bu\u0148ky.<\/p>\n
3. Embryo se rychle zmraz\u00ed, aby byl \u010das na z\u00edsk\u00e1n\u00ed v\u00fdsledk\u016f genetick\u00e9ho testu.<\/p>\n
4. Zdrav\u00e9 embryo \u010di embrya jsou vybr\u00e1ny pro implantaci do d\u011blohy matky.<\/p>\n
Bezpe\u010dn\u00fd odb\u011br Lidsk\u00e9 embryo je v prvn\u00edch dnech shlukem nespecializovan\u00fdch bun\u011bk, kter\u00e9 se teprve pozd\u011bji vyvinou v bu\u0148ky specializovan\u00e9. Kdy\u017e se n\u011bkter\u00e1 z nespecializovan\u00fdch bun\u011bk odebere kv\u016fli genetick\u00e9mu testov\u00e1n\u00ed, v\u00fdvoji z\u00e1rodku to neubl\u00ed\u017e\u00ed.<\/p>\n
<\/p>\n
LUDMILA HAMPLOV\u00c1<\/p>\n
Lidov\u00e9 noviny<\/p>\n","protected":false},"excerpt":{"rendered":"
Speci\u00e1ln\u00ed vy\u0161et\u0159en\u00ed m\u016f\u017ee podstoupit embryo vznikl\u00e9 na klinice pro um\u011bl\u00e9 oplodn\u011bn\u00ed je\u0161t\u011b p\u0159ed zaveden\u00edm do mat\u010diny d\u011blohy. Posta\u010d\u00ed jedna bu\u0148ka.<\/p>\n<\/div>","protected":false},"author":1,"featured_media":18908,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-25445","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-zdravi"],"_links":{"self":[{"href":"https:\/\/www.invarena.cz\/index.php?rest_route=\/wp\/v2\/posts\/25445","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.invarena.cz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.invarena.cz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.invarena.cz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.invarena.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=25445"}],"version-history":[{"count":0,"href":"https:\/\/www.invarena.cz\/index.php?rest_route=\/wp\/v2\/posts\/25445\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.invarena.cz\/index.php?rest_route=\/wp\/v2\/media\/18908"}],"wp:attachment":[{"href":"https:\/\/www.invarena.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=25445"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.invarena.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25445"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.invarena.cz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25445"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}