Biology has clever ways to mask the effects of potentially harmful gene mutations. Scientists are investigating how this ‘buffering’ works — and how to exploit it.

Scientists found that some inherited traits can bypass the traditional rules of genetics, revealing a surprising new layer of inheritance beyond DNA.

A new gene therapy has been used to successfully treat a deadly childhood liver disease in mice that model the disease, according to researchers at UCL and Great Ormond Street Hospital. Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome is a lethal genetic disorder usually caused by a lack of the VPS33B protein, with children diagnosed with the condition rarely living beyond their first year of life.

Now, in a study published in Nature Communications, the UCL-GOSH team found that by injecting a healthy version of the gene into the body, they can treat the condition in mice lacking VPS33B. Crucially, the final version of the treatment, which specifically targeted the liver cells, caused no harm. In the earlier versions, the genes became abnormally activated and caused cancerous cells to grow and expand in some cases.

While more tests must be done before the treatment can be tested in humans, the researchers’ breakthrough offers hope to babies with this devastating disorder and their families. In the UK, as many as six pregnancies per year might be affected by ARC syndrome. Furthermore, the findings may promote improved understanding of why some treatments may cause cancer.