Bohring–Opitz syndrome (BOS) is a medical syndrome caused by a mutation in the ASXL1 gene. It is diagnosed by genetic testing and is characterised by characteristic craniofacial appearance, fixed contractures of the upper limbs, abnormal posture, feeding difficulties, intellectual disability, small size at birth, and failure to thrive. Some of these features are shared with other genetic syndromes.

Genetically, de novo truncating mutations in ASXL1 have been shown to account for approximately 50% of Bohring–Opitz syndrome cases.

The syndrome is extremely rare, with fewer than 80 known cases worldwide. The leading cause of death is respiratory infections. Children with BOS can have feeding difficulties, recurring respiratory infections, sleep apnea, developmental delay, failure to thrive, abnormal hair density and length, Wilm’s Tumors, brain abnormalities, silent aspiration, and other issues.

There have been few individual epidemiological studies of CMML, due to the difficulty in the disease classification. CMML has an estimated incidence of less than 1 per 100,000 persons per year.

The median age of diagnosis is 65–75. CMML has a propensity for males rather than females, at a ratio of 1.5–3:1.

A new method developed using data from the M.D. Anderson Cancer Center found that a haemoglobin level of 2.5 x 10/L, >0% immature myeloid cells, >10% bone marrow blasts causes a reduced overall survival. This data allows cases of CMML to be stratified into low, intermediate-1, intermediate-2 and high risk groups. These groups have median survival times of 24, 15, 8 and 5 months respectively.

The myeloproliferative neoplasms (MPNs), previously myeloproliferative diseases (MPDs), are a group of diseases of the bone marrow in which excess cells are produced. They are related to, and may evolve into, myelodysplastic syndrome and acute myeloid leukemia, although the myeloproliferative diseases on the whole have a much better prognosis than these conditions. The concept of myeloproliferative disease was first proposed in 1951 by the hematologist William Dameshek. In the most recent World Health Organization classification of hematologic malignancies, this group of diseases was renamed from "myeloproliferative diseases" to "myeloproliferative neoplasms". This reflects the underlying clonal genetic changes that are a salient feature of this group of disease.

The increased numbers of blood cells may not cause any symptoms, but a number of medical problems or symptoms may occur. The risk of thrombosis is increased in some types of MPN.

High amounts of ionizing radiation exposure can increase the risk of AML. Survivors of the atomic bombings of Hiroshima and Nagasaki had an increased rate of AML, as did radiologists exposed to high levels of X-rays prior to the adoption of modern radiation safety practices. People treated with ionizing radiation after treatment for prostate cancer, non-Hodgkin lymphoma, lung cancer, and breast cancer have the highest chance of acquiring AML, but this increased risk returns to the background risk observed in the general population after 12 years.

Exposure to anticancer chemotherapy, in particular alkylating agents, can increase the risk of subsequently developing AML. The risk is highest about three to five years after chemotherapy. Other chemotherapy agents, specifically epipodophyllotoxins and anthracyclines, have also been associated with treatment-related leukemias, which are often associated with specific chromosomal abnormalities in the leukemic cells.

Occupational chemical exposure to benzene and other aromatic organic solvents is controversial as a cause of AML. Benzene and many of its derivatives are known to be carcinogenic "in vitro". While some studies have suggested a link between occupational exposure to benzene and increased risk of AML, others have suggested the attributable risk, if any, is slight.

Although not a malignant neoplasm like other cancers, MPNs are classified within the hematological neoplasms. There are four main myeloproliferative diseases, which can be further categorized by the presence of the Philadelphia chromosome:

In 2008, the World Health Organization listed these diagnoses as types of MPD:

- Chronic myelogenous leukemia (BCR-ABL1–positive)

- Chronic neutrophilic leukemia

- Polycythemia vera

- Primary myelofibrosis

- Essential thrombocythemia

- Chronic eosinophilic leukemia (not otherwise specified)

- Mastocytosis