LONDON - A scientist set out her argument on Wednesday for being given a British license to conduct controversial experiments which would alter the DNA of human embryos.

Critics of the proposed research say it is effectively genetically modifying human embryos and represents a "slippery slope" towards a future of designer babies.

But speaking before a meeting of Britain's Human Fertilisation and Embryology Authority (HFEA) that will decide if she can go ahead, Kathy Niakan said the work could help improve infertility treatments and could ultimately provide "a deeper understanding of the earliest stages of human life."

"The only way we can understand human biology at this early stage is by further studying human embryos directly," she told reporters at a briefing in London.

Niakan plans to carry out her experiments using new gene-editing technology called CRISPR-Cas9 - a technology which is already the subject of fierce international debate amid fears it could be used to create designer babies to order.

CRISPR-Cas9 can enable scientists to find and change or replace any targeted gene, strategically editing out specific stretches of DNA.

Many scientists have described it as "game-changing", and Chinese biologists sparked an international outcry last year when they reported carrying out the first-ever experiments editing the genes of human embryos.

The HFEA, which is due to meet on Thursday to consider Niakan's application, has previously noted that British law bans genome editing of embryos for use in treatment, but allows it for research if done under an HFEA license.

Niakan, a stem cell scientist from London's Francis Crick Institute, said that if she is given permission, she would hope to be able to start the experiments "within months".

"Currently we have a very descriptive understanding of early human biology, but with no real functional insights into what those genes mean," she said.

"This (research) is important because miscarriages and infertility are extremely common but not very well understood."

"You never can predict where research will lead, but we hope it would be a great benefit for fertility treatments in the long term."

The first gene she plans to target is one called Oct4, which she believes may have a crucial role in the earliest stages of human foetal development.

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David King, director of the UK campaign group Human Genetics Alert, criticized Niakan's plans, saying they marked "the first step on a path that scientists have carefully mapped out towards the legalization of GM babies."

Niakan said her work was for research purposes only and the embryos would not be implanted into women.

She added that before any further steps are taken using gene editing in human embryos for potential implantation, it was "extremely important to continue the ethical discussions" on what could and should be allowed.