MicroRNA quantitative RT-PCR analysis of CMT1A Plasma

Objective: To determine if microRNA's (miR) are elevated in the plasma of individuals affected by the inherited peripheral neuropathy Charcot-Marie-Tooth Disease, type 1A (CMT1A), miR profiling was employed to compare control and CMT1A plasma.

Methods: We undertook a screen of CMT1A and control plasma samples to identify miRs that are elevated in CMT1A using a pilot screen of plasma miR by next generation sequencing, followed by validation of selected miRs by quantitative PCR, and correlation with clinical data and protein biomarkers.

Results: After an initial pilot screen, a broader screen confirmed elevated levels of several muscle-associated miRNAs (known as myomiRs) along with a set of miRs that are highly expressed in Schwann cells of peripheral nerve. Comparison to other candidate biomarkers for CMT1A (e.g. Neurofilament L, NfL) measured on the same sample set shows a comparable elevation of several miRs and ability to discriminate cases from controls. In addition, the putative Schwann cell miRs correlate with a recently described TMPRSS5 biomarker that is also elevated in CMT1A plasma, and this protein is most highly expressed in Schwann cells.

Conclusions: These studies identify a set of miRs that are candidate biomarkers for clinical trials in CMT1A. Some of the miRs may reflect Schwann cell processes that underlie the pathogenesis of the disease.