“…Furthermore, many available treatments have demonstrated their increased efficacy when started early in life, identifying age at treatment as a predictive factor for a better clinical outcome [ 156 , 158 , 165 , 183 , 184 , 185 , 194 , 263 , 264 ]. In particular, both experiences in animal models and MPSI patients showed an improvement in bone defects in cases of early treatments, considering ERT [ 184 ] and/or HSCT [ 265 , 266 , 267 ]. In view of this, a neonatal GT approach could be helpful because it allows for a very early treatment and, in parallel, it is associated with a reduced risk of immunological complications (i.e., immune response against the therapeutic enzyme).…”