{"id":3622,"date":"2019-10-13T12:00:06","date_gmt":"2019-10-13T09:00:06","guid":{"rendered":"http:\/\/blog.ulubat.org\/?p=3622"},"modified":"2019-10-12T22:23:08","modified_gmt":"2019-10-12T19:23:08","slug":"prenatal-tarama-testi-nipt","status":"publish","type":"post","link":"https:\/\/blog.ulubat.org\/index.php\/genel\/prenatal-tarama-testi-nipt\/","title":{"rendered":"Prenatal Tarama Testi: NIPT"},"content":{"rendered":"\n
\"\"<\/figure><\/div>\n\n\n\n

1997 y\u0131l\u0131nda Lo ve arkada\u015flar\u0131n\u0131n cff-DNA ke\u015ffi ile genetik bozukluklar\u0131n prenatal tespitinde b\u00fcy\u00fck bir ad\u0131m at\u0131ld\u0131. B\u00f6ylece Non \u0130nvaziv Prenatal Testler g\u00fcndeme geldi. \u015eu anda bir\u00e7ok avantaj nedeniyle \u00e7ok kolay bir \u015fekilde benimsenmi\u015f NIPT, klinik uygulamada b\u00fcy\u00fck bir yer edinirken anne adaylar\u0131 taraf\u0131ndan \u00e7ok tercih edilmektedir. 2011 y\u0131l\u0131ndan beri NIPT ticari olarak kullan\u0131l\u0131yor ve kullan\u0131m\u0131 gittik\u00e7e yayg\u0131nla\u015f\u0131yor. \u00a0Peki bu test neden birden bu kadar \u00e7ok kullan\u0131lmaya ba\u015fland\u0131? Testin ad\u0131ndan da anla\u015f\u0131ld\u0131\u011f\u0131 gibi bu test invaziv i\u015flem gerektirmeyen, anne ve bebek i\u00e7in herhangi bir risk i\u00e7ermeden yap\u0131lan, y\u00fcksek \u00f6zg\u00fcnl\u00fc\u011f\u00fc ve hassasl\u0131\u011f\u0131 olan bir testtir. <\/p>\n\n\n\n

 Cff-DNA\u2019n\u0131n\nke\u015ffi gebe bir kad\u0131n\u0131n kan\u0131nda Y kromozomuna ait DNA par\u00e7alar\u0131n\u0131n bulunmas\u0131 ile\nger\u00e7ekle\u015fmi\u015ftir. B\u00f6ylece cff-DNA prenatal d\u00f6nemde kromozomal anomalilerin\ntespitinde kullan\u0131lmaya ba\u015fland\u0131.<\/p>\n\n\n\n

     K\u0131saca\nNIPT olarak ifade etti\u011fimiz bu test, plasentadaki trofoblastlar\u0131n apoptozu\ns\u0131ras\u0131nda ortaya \u00e7\u0131kan DNA\u2019n\u0131n maternal dola\u015f\u0131mdaki tespitine dayan\u0131r.  NIPT, fetal kromozomal an\u00f6ploidilerin tespitinde\n(T21, T13, T18 monozomi X anomalilerinde), cinsiyetin belirlenmesinde, Rh\nuyumsuzlu\u011funda (gereksiz profilaktik tedaviden ka\u00e7\u0131nmak i\u00e7in), babal\u0131k\ntespitinde kullan\u0131l\u0131r. Cff-DNA 5. ve 7. haftalar aras\u0131nda maternal kanda\nbulunmaya ba\u015flasa da 11.-13. Haftalar aras\u0131nda maternal plazmadaki\nkonsantrasyonu 7,8-13,0 olarak belirlenmi\u015ftir. Bu 10. haftadan sonra NIPT\ntestinin uygulanabilece\u011fi anlam\u0131na gelirken 24 saatte bozulmas\u0131 b\u00fcy\u00fck bir\nk\u0131s\u0131tlama haline gelmektedir. Ayn\u0131 zamanda gestasyonel hafta artt\u0131k\u00e7a maternal\nplazmadaki fetal franksiyon da artmaktad\u0131r.<\/p>\n\n\n\n

      Cff-DNA\u2019n\u0131n\nplasental k\u00f6kenli olmas\u0131 ve maternal plazmada bulunmas\u0131 mevcut prenatal tarama\ntestlerine g\u00f6re daha fazla avantaja sahip olmas\u0131n\u0131 sa\u011fl\u0131yor. NIPT\u2019n\u0131n\navantajlar\u0131ndan biri ise di\u011fer testler gibi belirli bir s\u00fcre i\u00e7inde yap\u0131lmas\u0131\ngerekmemektedir.<\/p>\n\n\n\n

   Yap\u0131lan\nbir\u00e7ok ara\u015ft\u0131rma taraf\u0131nda NIPT\u2019n\u0131n Down sendromu, Trizomi 18, Trizomi 13 ve\ncinsiyet kromozom an\u00f6ploidileri i\u00e7in alg\u0131lama oranlar\u0131 s\u0131ras\u0131yla %99 %96 ve %92\nolarak belirlenmi\u015ftir.<\/p>\n\n\n\n

\u00a0\u00a0\u00a0\u00a0 \u00a0NHC (National Health Service)<\/strong><\/em> mikrodelesyonlar ve sex kromozom anormallikleri i\u00e7in NIPT\u2019yi kullanmam\u0131z\u0131 \u00f6nermemektedir. Ayr\u0131ca NIPT hem y\u00fcksek hem de d\u00fc\u015f\u00fck riskteki gebelerdeki an\u00f6ploidi tespiti i\u00e7in \u00e7ok duyarl\u0131 oldu\u011fu g\u00f6sterilmi\u015ftir. ACOG (Amerikan Jinekoloji ve Obstetrik Derne\u011fi) \u00f6nergeleri ise \u015fu anda \u00e7o\u011ful gebelikler i\u00e7in NIPT’yi \u00f6nermemektedir. \u00c7o\u011ful gebeliklerde an\u00f6ploidiler her bir fetal kesenin amniyosentezi ile tespit edilmektedir. Ayr\u0131ca 2014 y\u0131l\u0131 itibariyle, 1p, 5p, 15q, 22q,11q, 8q ve 4p.40,41 kromozomlar\u0131ndaki anormalliklerin tespiti i\u00e7in testler ticari olarak mevcuttur. Ancak bu testler \u00f6zg\u00fcll\u00fc\u011f\u00fc ve hassasiyeti hen\u00fcz onaylanmam\u0131\u015ft\u0131r. Alt kromozomal kopya say\u0131s\u0131n\u0131n tespiti (\u00f6rne\u011fin, mikrodelesyonlar ve mikro bozulmalar) i\u00e7in cff-DNA kullanma yakla\u015f\u0131m\u0131, gereklili\u011fi a\u00e7\u0131s\u0131ndan s\u0131n\u0131rl\u0131d\u0131r. Petersen ve di\u011f. tahmini d\u00fc\u015f\u00fck pozitif \u00f6ng\u00f6r\u00fc de\u011ferleri (%0-21) ve daha y\u00fcksek yanl\u0131\u015f pozitif oranlar\u0131 y\u00fcz\u00fcnden \u015fe\u00e7ilen mikrodelesyon sendromlar\u0131 (Cri du chat (5p sendromu), Prader-Willi (Angelman sendromu),22q11del (DiGeorge sendromu ve 1p36 delesyon sendromu), ortak anoploidler ile kar\u015f\u0131la\u015ft\u0131r\u0131ld\u0131\u011f\u0131nda \u00f6nde gelen d\u00fc\u015f\u00fck prevalans g\u00f6z \u00f6n\u00fcne al\u0131nd\u0131\u011f\u0131nda klinik do\u011frulama \u00e7al\u0131\u015fmalar\u0131 d\u00fc\u015f\u00fck riskli hastalar i\u00e7in de\u011feri g\u00f6sterinceye kadar genel pop\u00fclasyonda kullan\u0131lmamal\u0131d\u0131r. Cff-DNA testinin Down sendromu i\u00e7in daha iyi performans g\u00f6sterdi\u011fi, ancak preeklampsi, fetal b\u00fcy\u00fcme k\u0131s\u0131tlamas\u0131 olan di\u011fer gebeliklerde s\u0131ral\u0131 taraman\u0131n daha iyi oldu\u011fu g\u00f6sterilmi\u015ftir.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Amerikan Kad\u0131n Do\u011fum ve Jinekologlar Koleji\u2019nde rutin olarak cff-DNA taramas\u0131 \u00f6nerilmemektedir. \u00c7\u00fcnk\u00fc, NIPT, serum testlerinden daha y\u00fcksek hassasiyete sahip olsa da bir tan\u0131 testi de\u011fildir ve pozitif \u00e7\u0131kan bir NIPT sonucu mutlaka invaziv test ile onaylanmal\u0131d\u0131r. NIPT ve geleneksel invaziv testler aras\u0131ndaki uyumluluk \u00f6rnekleri y\u00fcksek olsa da birka\u00e7 yanl\u0131\u015f pozitif veya uyumsuz vaka bildirilmi\u015ftir. Bu vakalar a\u011f\u0131rl\u0131kl\u0131 olarak s\u0131n\u0131rl\u0131 plasental mozaik\u00e7ilikten (CPM) kaynaklanmaktad\u0131r. CPM, T18 ve T13\u2019te \u00f6zel bir \u00f6nem ta\u015f\u0131maktad\u0131r.\u00a0 Di\u011fer tutars\u0131zl\u0131k nedenleri aras\u0131nda d\u00fc\u015f\u00fck fetal fraksiyon kaynakl\u0131 yanl\u0131\u015f negatifler de bulunur. Bu y\u00fczden sadece y\u00fcksek riskli olarak tan\u0131mlanm\u0131\u015f kad\u0131nlarda kullan\u0131lmas\u0131 \u00f6nerilmektedir. Ve ACOG bu y\u00fcksek riski kad\u0131nlar\u0131 tan\u0131mlamak i\u00e7in baz\u0131 maddeler haz\u0131rlam\u0131\u015ft\u0131r bunlar; anne ya\u015f\u0131 35 veya daha \u00fcst\u00fc olmas\u0131, fetal ultranosografi taraf\u0131ndan an\u00f6ploidi i\u00e7in y\u00fcksek risk bulunmas\u0131, annenin daha \u00f6nce trizomi \u00f6yk\u00fcs\u00fcne sahip \u00e7ocu\u011fu olmas\u0131, birinci trimesterde yap\u0131lan s\u0131ral\u0131-ba\u011f\u0131ml\u0131 veya d\u00f6rtl\u00fc testlerin sonu\u00e7lar\u0131n pozitif olmas\u0131.<\/p>\n\n\n\n

   Elde\nedilen verilere g\u00f6re NIPT’nin tan\u0131t\u0131lmas\u0131 invaziv prenatal tan\u0131 prosed\u00fcrlerinin\nsay\u0131s\u0131n\u0131n ve bu prosed\u00fcrlere ba\u011fl\u0131 i\u015flem hasar\u0131n\u0131n ve fetal kayb\u0131n\u0131n azalmas\u0131n\u0131\nsa\u011flad\u0131, ancak baz\u0131 klinisyenlere g\u00f6re bu azalma olumsuz sonu\u00e7lar do\u011furdu. Bu\nklinisyenlerden biri olan Beaudet\u2019nin \u00f6ne s\u00fcrd\u00fc\u011f\u00fcne g\u00f6re invaziv testlerin\nazalmas\u0131 daha az say\u0131da delesyon sendromu vakas\u0131n\u0131n saptanmas\u0131na bu da engelli\nbebeklerin do\u011fum say\u0131s\u0131n\u0131n artmas\u0131na neden oldu. Ayr\u0131ca yetersiz uygulama ayn\u0131\nzamanda invazif i\u015flemin kalitesini etkiyor ve b\u00f6ylece fetal kay\u0131p ve enfeksiyon\noranlar\u0131nda da y\u00fckselme meydana geliyor. Bu sonu\u00e7a nas\u0131l elde ettiklerine\ngelirsek 2000-2014 y\u0131llar\u0131 aras\u0131ndaki invaziv i\u015flemlerde bebek d\u00fc\u015fme olas\u0131l\u0131\u011f\u0131\nile 2000-2017 aras\u0131ndaki olas\u0131l\u0131\u011f\u0131 \u00f6l\u00e7m\u00fc\u015fler ve 2000-2014 olas\u0131l\u0131\u011f\u0131 d\u00fc\u015f\u00fck\n\u00e7\u0131km\u0131\u015ft\u0131r.  Yani demi\u015fler ki NIPT\nkullan\u0131m\u0131, invaziv i\u015flemelerinin say\u0131s\u0131n\u0131 azaltmas\u0131n\u0131n yan\u0131 s\u0131ra ayn\u0131 zamanda\ntecr\u00fcbe gerektiren bu i\u015flemelerin kalitesini de azalt\u0131yor. Bu e\u011filim devam\nederse, yetenekli klinisyenlerin e\u011fitimi ve bunun s\u00fcrd\u00fcr\u00fclmesi gelecekteki\ndo\u011fum \u00f6ncesi bak\u0131m i\u00e7in de bir \u00e7eli\u015fkidir. Ayr\u0131ca \u00f6zel sekt\u00f6rde NIPT\u2019nin d\u00fc\u015f\u00fck\nriskli kad\u0131nlara ve ilk se\u00e7enek olarak \u00f6nerilmesi vard\u0131r. Hastalar i\u00e7in maddi olmayan faydalar ve daha\nerken ve daha g\u00fc\u00e7l\u00fc sonu\u00e7lar, NIPT\u2019n\u0131n evrensel kullan\u0131m\u0131n\u0131 daha da\nartt\u0131rmaktad\u0131r. \u015eu anda NIPT\u2019n\u0131n fetal cinsiyetinin belirlenmesinde kullan\u0131m\u0131\netik sebeplerden dolay\u0131 yasal de\u011fildir. NIPT\u2019n\u0131n bu y\u00f6n\u00fcn\u00fcn fetal cinsiyete\nba\u011fl\u0131 k\u00fcrtaj i\u015flemlerinin say\u0131s\u0131n\u0131 artt\u0131raca\u011f\u0131 d\u00fc\u015f\u00fcn\u00fclmektedir.<\/p>\n\n\n\n

   NIPT\nbir g\u00fcn tamamen geleneksel taraman\u0131n yerini alacakt\u0131r ama tan\u0131 y\u00f6ntemi olarak\nde\u011fil. NIPT i\u00e7in 3 tane uygulama \u015fekli belirtilmi\u015ftir.<\/p>\n\n\n\n

  1. Tarama ve invaziv testleri aras\u0131nda ortak bir yol<\/li>
  2. \u0130nvaziv test i\u00e7in yedek olarak<\/li>
  3. \u0130lk ad\u0131m olarak<\/li><\/ol>\n\n\n\n

         Prenatal\ntarama i\u00e7in cff-DNA, geleneksel tarama ile kar\u015f\u0131la\u015ft\u0131r\u0131ld\u0131\u011f\u0131nda \u00e7ok daha\npahal\u0131d\u0131r. Hollanda\u2019da bu test standart bir pr\u00f6sed\u00fcr halinde iken, Kanada\u2019n\u0131n\nbirka\u00e7 eyaletinde bu test hastalara \u00fccretsiz sa\u011flanmaktad\u0131r. Bizim \u00fclkemizde\nise bu test SGK taraf\u0131ndan kar\u015f\u0131lanmamakta ve \u00f6zel sekt\u00f6rde mevcuttur. \u00d6zel\nsekt\u00f6rde ise fiyatlar 2500-3300 \u20ba aras\u0131nda de\u011fi\u015fmektedir. <\/p>\n\n\n\n

    Kaynak\u00e7a:<\/p>\n\n\n\n

    1. https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/31214330<\/a><\/li>
    2. https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/?term=S.+Drury+and+NIPT<\/a><\/li>
    3. https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/25653560<\/a><\/li>
    4. https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/25289665<\/a><\/li>
    5. https:\/\/pdfs.semanticscholar.org\/d0ec\/6a1cd319cc2f395d4d4432b4ac171009822d.pdf<\/a><\/li><\/ol>\n\n\n\n

      Not: Bu\nyaz\u0131da yer alan resim ve tablo https:\/\/www.ncbi.nlm.nih.gov\/pubmed\/31214330<\/a> adresinde yer\nalan makaleden al\u0131nm\u0131\u015ft\u0131r.<\/p>\n","protected":false},"excerpt":{"rendered":"

      1997 y\u0131l\u0131nda Lo ve arkada\u015flar\u0131n\u0131n cff-DNA ke\u015ffi ile genetik bozukluklar\u0131n prenatal tespitinde b\u00fcy\u00fck bir ad\u0131m at\u0131ld\u0131. B\u00f6ylece Non \u0130nvaziv Prenatal<\/p>\n","protected":false},"author":190,"featured_media":3626,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"acf":[],"views":1979,"_links":{"self":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/3622"}],"collection":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/users\/190"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/comments?post=3622"}],"version-history":[{"count":1,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/3622\/revisions"}],"predecessor-version":[{"id":3628,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/3622\/revisions\/3628"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/media\/3626"}],"wp:attachment":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/media?parent=3622"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/categories?post=3622"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/tags?post=3622"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}