A story from Charcot-Marie-Tooth News highlights the necessity for genetic testing and a physical examination prior to chemotherapy in order to prevent nerve damage in people with asymptomatic Charcot-Marie-Tooth disease (CMT). It is generally understood that patients with the disorder can sustain severe nerve damage from the chemotherapy agent vincristine, but people with that are unaware that they have CMT may use unwittingly use vincristine can cause themselves harm.
Charcot-Marie-Tooth disease is a neurological disorder in which significant muscular atrophy and sensation problems occur in the peripheral nerves. However, there are some people who carry the mutations responsible for CMT but never experience symptoms. To learn more about Charcot-Marie-Tooth disease, click here.
Vincristine or leurocristine, marketed under the brand name Oncovin, is a chemotherapy drug used primarily for the treatment of several types of leukemia, Hodgkin’s lymphoma, small cell lung cancer, and neuroblastoma. It is derived from the Madagascar periwinkle (Catharanthus roseus). It is part of several chemotherapy regimens and works by preventing cancer cells from dividing properly. Although generally considered safe, it is known to have some neurological side effects which is why people with CMT are urged to avoid using it.
A new report cites the example of a 56 year old woman that was suffering from diffuse large B-cell lymphoma. Her doctors prescribed her a chemotherapy regimen hat included vincristine, and only four days after her first cycle, she began to lose sensation in her fingers and toes. Eventually, she lost feeling in her limbs entirely, causing her to become completely debilitated. Upon closer examination, the doctors noticed that she had high-arched feet, and trait that was also carried by other members of her family. High arched feet are a common physical sign of CMT, and subsequent genetic testing proved that the woman and her family all had CMT but suffered no symptoms.
Changing to an alternative chemotherapy resulted in the resolution of her symptoms. The authors warn that it is necessary for a physical examination and a genetic test to be administered for people who are about to take any chemotherapy regimen that includes vincristine. Without it, people who have asymptomatic CMT could experience severe disability.
