The Human Fertilisation and Embryology Authority has given the go-ahead for scientists at the Francis Crick Institute to carry out research using new gene editing techniques on human embryos for the first time.

Their study plans to look at the first seven days of a fertilised egg’s development, when it grows from just a single cell to around 250, to further understanding of the genes necessary for this process and perhaps shed more light on the reasons for miscarriage.

The knowledge could also improve embryo development after in vitro fertilisation (IVF) and thus boost the success rate, and might provide better clinical treatments for infertility, using conventional medical methods, the researchers note.

Many of the genes switched on after fertilisation are only found in humans, making animal research in this area difficult. The team are planning to use gene-editing tools to switch off certain genes within human embryos and observe the effect. 

The research still need ethical approval before the programme begin and, in line with current HFEA regulation, any donated embryos will be used for research purposes only and cannot be used in treatment. 

While the move is a first for the UK, Chinese researchers have already attempted to modify genes in human embryos, with a view to ultimately being able to repair faulty genes responsible for the development of inherited illnesses such as muscular dystrophy. 

However, the field has long been surrounded by controversy, with critics fearing that gene-editing could be used to create a generation of so-called ‘designer’ babies.