For example, Neurofibromatosis‐Noonan syndrome (NFNS) and Watson syndrome (WS), both caused by pathogenic variants in the NF1, present with phenotypes similar to NSDs: NFNS presents with a NS facial gestalt, short stature, skeletal defects, and multiple CALs, while WS presents with short stature, PVS, multiple CALs, and intellectual disability (Tartaglia & Gelb, 2010). This evidence concerns the gene NF1 and perivascular space measurement.