After being diagnosised with polycythemia vera (PV), David Gelly finds himself on a new journey. In this video, he explains his diagnosis of PV—one of a group of rare, chronic blood cancers known as myeloproliferative neoplasms (MPNs).

MPNs are rare, chronic blood cancers. Chronic conditions last for a long period of time and may never go away. MPNs can be classified based on the presence or absence of a chromosomal abnormality called the Philadelphia chromosome. There are several types of Philadelphia chromosome–negative MPNs:

– Polycythemia vera
– Essential thrombocythemia
– Myelofibrosis

Each type of MPN is characterized by a particular pattern of abnormal blood cell production that usually impacts one blood cell type more than the others. MPNs are progressive conditions, meaning that they worsen over time.

MPNs can affect people at any age, but they are more common in older adults.Mutations, or changes in certain genes, are thought to be a major cause of what are known as Philadelphia chromosome–negative MPNs, or “classical” MPNs. Even people who do not have these mutations may have MPNs.