PDGFRB germline variants with a higher constitutive activity, such as p.P584R or p.W566R, have been identified in patients with Kosaki overgrowth syndrome, who exhibit alterations in bones, the brain and the skin.17, 18. The gene discussed is PDGFRB; the disease is skeletal overgrowth-craniofacial dysmorphism-hyperelastic skin-white matter lesions syndrome.