Considering that PVS is a classic cardiac feature of NS, the elevated prevalence of PVS in patients with NF1 in-frame mutations, together with the increased incidence of NS-like related features in NF1 patients with PVS, favors the hypothesis that some NF1 specific mutations may predispose more toward an NS-like phenotype rather than to a classic NF1 phenotype. This evidence concerns the gene NF1 and perivascular space measurement.