Recently I was asked about CMT (Charcot-Marie-Tooth disease) or HMSN (hereditary motor and sensory neuropathy) and whether it affects the brain. According to my sources, including NIH and the CMT foundation, this inherited neurological condition rarely affects the brain. It is a common disorder, however, affecting about 1 in 2,400 or 2,500 people in the USA. It is named for the three physician who first identified it in 1886: Jean-Martin Charcot and Pierre Marie in France, and Howard Henry Tooth in England. Fortunately, it is not considered a fatal disease and people usually have a normal life expectancy. If it runs in your family and you want to be tested, genetic counseling can usually reveal if individuals are likely to pass on their mutated gene(s) to their biological children. More tomorrow.