Indicative features in children with JMML/NF-1 are the presence of ≥6 cutaneous café au lait spots and/or the family history; other characteristics of NF-1, such as neurofibromas, optic pathway gliomas, bone lesions and neurological abnormalities, usually manifest only later. The gene discussed is NF1; the disease is juvenile myelomonocytic leukemia.