Mosaic variants in PTPN11 are associated with isolated juvenile myelomonocytic leukemia (JMML, a neoplasm NS patients are prone to develop),8 as well as other types of cancers, including astrocytoma (COSMIC Database: Genomic Mutation ID: COSM13036). This evidence concerns the gene PTPN11 and juvenile myelomonocytic leukemia.