With more than 130 genes involved, the genetic diagnosis of Charcot-Marie-Tooth (CMT) disease and associated neuropathies is a complex process which is not always conclusive. According to data from a cohort of 1,515 patients monitored by Professor Mary Reilly’s team in England :
- 77% of patients were able to receive a genetic diagnosis, although this proportion fell below 50% for axonal and purely motor forms.
- Whole genome sequencing was carried out on 233 cases as part of the UK’s “100,000 genomes project”, enabling 46 people to be diagnosed. It should be noted that for half of the cases, the results came back negative following sequencing, and it was only after the data had been analysed by the team at the centre specialising in peripheral neuropathies that the diagnosis was finally made.
Although the genes involved have yet to be identified, and technical advances will help to reduce the number of misdiagnoses, the authors stress the importance of taking into account the genetic complexity of CMT: sometimes the disease is not monogenic or the penetrance of the genetic anomaly is not complete.
