NfL and pNfH are increased in Friedreich’s ataxia

Objective To assess neurofilaments as neurodegenerative biomarkers in serum of patients with Friedreich’s ataxia. Methods Single molecule array measurements of neurofilament light (NfL) and heavy chain (pNfH) in 99 patients with genetically confirmed Friedreich’s ataxia. Correlation of NfL/pNfH serum levels with disease severity, disease duration, age, age at onset, and GAA repeat length. Results Median serum levels of NfL were 21.2 pg/ml (range 3.6–49.3) in controls and 26.1 pg/ml (0–78.1) in Friedreich’s ataxia ( p = 0.002). pNfH levels were 23.5 pg/ml (13.3–43.3) in controls and 92 pg/ml (3.1–303) in Friedreich’s ataxia ( p = 0.0004). NfL levels were significantly increased in younger patients (age 16–31 years, p