Linear and whorled nevoid hypermelanosis (LWNH) is characterized by hyperpigmentation following Blaschko’s line which usually occurs in infancy or early childhood. Affected individuals have no accompanying extracutaneous manifestations. Recently, a postzygotic mutation (p.Asp110Gly) the KITLG gene was identified on hyperpigmented skin of patient with LWNH. KIT-ligand (KITLG), also known as stem...