NF1 and juvenile myelomonocytic leukemia: Missense variants in codons 844–848 of NF1 are associated with a higher prevalence of symptomatic spinal neurofibromas (p.Leu844, p.Cys845, p.Ala846, p.Leu847, p.Gly848) and superficial pNFs (p.Cys845, p.Ala846), and an increased risk of developing MPNSTs and other malignancies including rhabdomyosarcomas, JMML, and neuroblastomas caused by the p.Leu847Pro variant.