Hereditary peripheral neuropathies diagnosed by next-generation sequencing

Next-generation sequencing (NGS) is a genetic technique used to determine the order of nucleotides in DNA. The technique has proved to be more efficient than the traditional method, Sanger sequencing, for sequencing multiple genes. NGS is now being used to diagnose disorders in which multiple genes are involved. This study has examined whether next-generation sequencing produces a greater number of positive diagnoses than its traditional counterpart in patients with suspected hereditary peripheral neuropathy.

This study is a retrospective review of samples from 103 patients investigated for hereditary peripheral neuropathy, received by Telemark Hospital in the period 2012-14. After exclusion of duplication/deletion of PMP22, 96 samples were analysed by NGS with physical enrichment of 52 hereditary peripheral neuropathy genes.

A genetic cause was identified in 35 patients (34%) with peripheral neuropathy, of which 28 (27%) were point mutations identified by NGS.

Of the pathogenic point mutations identified in this study, 12 were in genes that would previously have been analysed by Sanger sequencing in our department, whereas 16 were in genes that would not previously have been tested.