Which patient groups have the highest prevalence of Charcot-Marie-Tooth (CMT) disease?

Updated: Feb 19, 2019
  • Author: Francisco de Assis Aquino Gondim, MD, PhD, MSc, FAAN; Chief Editor: Nicholas Lorenzo, MD, MHA, CPE  more...
  • Print
Answer

Answer

CMT is found world wide in people of all races and ethnic groups. [12]

Some rare CMT subtypes, in particular autosomal recessive, are largely restricted to particular racial groups.

In the United States, CMT may be less common among black people. Whether this represents a lower frequency of the specific mutations or protection from disease manifestation through unknown disease-modifying genes remains unclear.

CMT subtypes may be inherited in an autosomal dominant or recessive or an X-linked pattern.

Importantly, CMTX (similar to other X-linked diseases), while certainly more severe in men, is not uncommonly associated with clear disease in women, which may even be severe, most likely because of unequal inactivation of the X chromosome, which may result in predominant expression of the abnormal CX32 allele in nerves.

Reportedly, CMT may have a more severe phenotype in men, possibly because of environmental (nerve trauma) or X-linked neuroprotective factors, but, in practice, this impression is of little value because of the great phenotypic variability between and within families.

Age of onset is variable according to subtype, penetrance, familial phenotype, and ascertainment bias. Most symptoms start during childhood but may go unnoticed. In the authors' experience, onset of disease is noticed much earlier in large families with a lot of knowledge of their disease.

Diagnosis is usually not made until late adolescence or early or late adulthood. Exceptions are more severe phenotypes such as DSS and CHN.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!