英國首批“三親嬰兒”有望2018年誕生

A final scientific review has given a green light for British doctors to carry out mitochondrial replacement, which creates babies with DNA from three people in order to avoid genetic disease.

一項最終科學(xué)審查為英國醫(yī)生進(jìn)行線粒體置換開了綠燈，線粒體置換會誕生擁有3個人的DNA的嬰兒，目的是避免基因疾病。

The Human Fertilisation and Embryology Authority, the UK regulator, commissioned the review to assess new research on the safety of mitochondrial therapy that has been published since Parliament legalised the technique last year.

英國監(jiān)管機(jī)構(gòu)人類生育和胚胎學(xué)管理局(Human Fertilisation and Embryology Authority, HFEA)委托了這次審查，以評估英國議會去年將這項技術(shù)合法化后發(fā)表的有關(guān)線粒體療法安全性的新研究。

Although some potential hazards were identified, the review panel found that the risks were not great enough to stop the HFEA implementing the legislation. It recommended approval of mitochondrial therapy for “cautious use in specific circumstances”.

盡管發(fā)現(xiàn)了一些潛在的危害，審查小組認(rèn)為，這些風(fēng)險還不足以阻止HFEA實施立法。審查小組建議，批準(zhǔn)線粒體療法在“特定情況下謹(jǐn)慎使用”。

Andy Greenfield, panel chair, said this approach “strikes the right balance between offering access to this exciting new treatment to couples at real risk of having a . . . child with mitochondrial disease, while doing all we can to ensure that the treatment is safe and effective”.

審查小組主席安迪•格林菲爾德(Andy Greenfield)表示，這種做法“在兩者之間達(dá)到了正確的平衡：一邊是為那些真正面臨風(fēng)險，可能生下一個……患有線粒體疾病的孩子的夫婦提供使用這種令人興奮的新療法的機(jī)會，一邊是盡我們所能確保療法安全有效”。

The HFEA will meet on December 15 to consider the report. If it accepts the scientific recommendations, as expected, and invites applications to carry out mitochondrial replacement, these might be approved in time for treatment to begin in the spring. Then, Britain’s first “three-parent babies” — as they are called in the media but not in the scientific world — could be born in 2018.

HFEA將在12月15日開會審議這份報告。如果該局如預(yù)期一般接受了這些科學(xué)建議，并且邀請有關(guān)方面提出進(jìn)行線粒體置換的申請，這些申請可能得到及時批準(zhǔn)，治療便可在明年春天開始。此后，英國的第一個“三親嬰兒”——這是媒體的叫法，科學(xué)界并不這么說——或?qū)⒃?018年出生。

“We expect the first applications to come from Newcastle University, where they have huge experience looking after patients with mitochondrial disease,” said Frances Flinter, professor of clinical genetics at King’s College London and a member of the review panel.

“我們預(yù)計紐卡斯?fàn)柎髮W(xué)(Newcastle University)將成為首批申請者之一，這所大學(xué)在照顧線粒體疾病患者方面擁有豐富經(jīng)驗，”審查小組成員、倫敦國王學(xué)院(King’s College London)臨床遺傳學(xué)教授弗朗西絲•弗林特(Frances Flinter)表示。

“This is obviously great news,” said Professor Doug Turnbull, who leads Newcastle’s mitochondrial programme. “This gives women who have mitochondrial DNA mutations reproductive choice.”

“這顯然是個好消息，”紐卡斯?fàn)柎髮W(xué)線粒體項目負(fù)責(zé)人道格•特恩布爾(Doug Turnbull)教授說，“這給了那些線粒體DNA發(fā)生突變的女性生育的選擇。”

Living cells depend on mitochondria to provide energy for every biological activity. These microscopic power packs have their own DNA, separate from the main genome in the cellular nucleus, and genetic defects can cause a wide range of medical problems from muscle weakness to heart failure and brain disease.

活細(xì)胞依賴線粒體為每一種生物活動提供能量。這些微觀的能量組擁有不同于細(xì)胞核中主基因組的自身的DNA，線粒體基因缺陷可能導(dǎo)致從肌肉無力、心衰竭到腦部疾病等多種疾病。

Treatment involves an IVF procedure in which the mother’s faulty mitochondria are replaced with healthy ones from an egg donor. These donated mitochondrial genes represent only a tiny fraction of the maternal contribution to the resulting baby’s DNA but they mean that its genetic inheritance comes from two women and one man.

線粒體治療包含體外受精過程，用卵子捐獻(xiàn)者的健康線粒體替換母親有缺陷的線粒體。在嬰兒的DNA中，捐獻(xiàn)的線粒體的基因在母方基因中的比例非常微小，但這意味著嬰兒的基因傳承將來自兩名女性和一名男性。

Among the new scientific evidence considered by the HFEA review was a puzzling paper published on Wednesday in the journal Nature, which suggested that transplantation might occasionally fail to eliminate faulty mitochondria. But the panel concluded that this was unlikely to pose a serious threat in practice.

審查考慮的新科學(xué)證據(jù)包括本周三《自然》(Nature)雜志在線發(fā)表的一份令人困惑的論文，該文認(rèn)為，移植有時可能無法完全去除缺陷線粒體。但審查小組的結(jié)論是，在實踐中這不太可能構(gòu)成嚴(yán)重威脅。

The review also found that an alternative approach — screening IVF embryos for mitochondrial abnormalities before implantation — was not a sufficiently reliable way to prevent mitochondrial disease.

審查還發(fā)現(xiàn)，替代辦法——在將體外受精胚胎植入母體前篩查線粒體異常——作為預(yù)防線粒體疾病的方法不夠可靠。

At least one three-parent baby already exists. A healthy boy was born earlier this year following mitochondrial treatment in Mexico where there is no legislation covering the technique. “This famous Mexican baby seems OK but we don’t have enough details really to comment,” said Robin Lovell-Badge of the Crick Institute in London, another member of the HFEA panel.

世界上至少已經(jīng)存在一名三親嬰兒。今年早些時候，一個團(tuán)隊在沒有關(guān)于這項技術(shù)的立法的墨西哥使用線粒體療法讓一個健康的男嬰出生。“這個著名的墨西哥嬰兒似乎狀態(tài)良好，但我們確實沒有掌握足夠的細(xì)節(jié)發(fā)表評論，”審查小組成員、倫敦弗朗西斯•克里克研究所(Francis Crick Institute)的羅賓•洛弗爾-巴杰(Robin Lovell-Badge)說。