Some neurologists argue that having made a clinical diagnosis of an untreatable genetic condition, there is no need to undertake genetic testing to identify the precise genetic diagnosis. This nihilistic attitude is not uncommon in the increasingly financially challenging health service environment.

In this issue, Ingram et al1 eloquently report the process of identifying a rare mutation in the SLC5A7 gene as a cause of distal hereditary motor neuropathy with vocal cord paresis. Their paper provides an ideal opportunity to review the arguments for doing molecular testing for untreatable genetic conditions.

The most compelling reason to do molecular genetic testing is that patients want an accurate diagnosis. It is important not to underestimate the benefit for patients of receiving an accurate diagnosis, especially in terms of them coming to terms with their disease. A precise genetic diagnosis also allows a much more accurate prognosis and can have implications for medical management, for example a child with a slowly progressive axonal neuropathy that clinically resembles Charcot Marie Tooth disease type 2 (CMT2) …