With the development of the anti-oligonucleotide (ASO) Nusinersen, there are studies where both neurofilament light chain (pNf-L), using ultrasensitive single molecule matrix technology Simoa® (Single Molecule Array), manufacturer by Quanterix, Billerica, MA, USA., and heavy chain (pNfH), using the ProteinSimple® (Ella immunoassay platform) manufacturer by Bio-echne, San Jose, CA, USA, as well as its correlation with Nf in CSF, have been analyzed in plasma as blood biomarkers in different types of SMA. Here, NFASC is linked to proximal spinal muscular atrophy.