The gene genie is well and truly out of the bottle...

US gene-testing giant 23andMe went bankrupt this year, raising concerns about the safety of customer data, prompting questions about the value of popular DIY tests. Jane Symons reports

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Genetic testing has transformed healthcare and led to a new era of diagnostics and precision medicine.

Cancer patients were among the first to benefit from these breakthroughs, but genetic research is now shaping our approach to a wide range of common conditions including heart disease, diabetes and stroke.

Genomic sequencing - mapping the entire DNA blueprint of the body and all its functions - is also giving new hope to families of children born with rare, and previously difficult to diagnose conditions. Getting an accurate diagnosis in infancy enables earlier intervention to reduce symptoms and may open the door to new treatments.

Genomics advances, and the falling cost of these technologies, have also led to a booming industry in commercial tests, which promise to provide personal insights into a consumer's individual risk of different diseases.

Here we've asked three experts in the field to explain how it is improving healthcare here and now, and what it might bring in the future.

What is a genetic test?

There are actually two types: whole genome sequencing, which is often abbreviated to WGS, and targeted genetic tests which look for specific high-risk genes - such as the BRCA cancer genes - or collections of genes that could add up to an increased risk of a health problem.

As the name suggests, WGS maps a patient's entire genome. This includes the segments of DNA known as genes, which produce the proteins needed to drive every function in the body, plus sequences known as non-coding DNA which make up 98% of our genome.

Dr Ellen Thomas, chief medical officer at Genomics England, says: “In the past, this would have been called 'junk DNA', but we just didn't understand it well enough. We now know that newly discovered non-coding DNA changes are among the most common causes of neuro-developmental conditions in children.”