Variable response of germline activating PDGFRB variants to receptor tyrosine kinase inhibitors: implications for treatment.

Platelet-derived growth factor receptor-beta (PDGFRβ) is a receptor tyrosine kinase that plays significant roles in cell growth, proliferation, and differentiation. Germline variants of PDGFRB can lead to several different diseases, e.g. infantile myofibromatosis, Kosaki overgrowth syndrome, Penttinen premature aging syndrome, ocular pterygium - digital keloid dysplasia, primary familial brain calcification, and others. Some variants cause the kinase to be constitutively active, even in the absence of ligand, while others lead to inactivation of signaling transduction mechanisms. Constitutive activation of PDGFRβ leads to increased cell growth, proliferation, and differentiation, which can lead to the development of tumors or other abnormal growths. The development of new therapies that target PDGFRβ is an active area of research, primarily in cancer treatment. However, these therapies have the potential to also provide effective treatment options for patients with germline variants of PDGFRB. Here, we provide a summary of recurrent activating germline variants reported in PDGFRB and examine their sensitivity to different tyrosine kinase inhibitors. We show that the respective amino acid substitutions respond differently to treatment with tyrosine kinase inhibitors that correlate with previous in vivo data. Our data may assist healthcare providers when deciding personalized treatment of patients with disorders associated with activating variants in PDGFRB.