<P> There are also several corrective surgical procedures that can be done to improve physical condition . </P> <P> The severity of symptoms vary widely even for the same type of CMT . There have been cases of monozygotic twins with varying levels of disease severity, showing that identical genotypes are associated with different levels of severity (see penetrance). Some patients are able to live a normal life and are almost or entirely asymptomatic . A 2007 review stated that "Life expectancy is not known to be altered in the majority of cases". </P> <P> The disease is named after those who classically described it: Jean - Martin Charcot (1825--1893), his pupil Pierre Marie (1853--1940) ("Sur une forme particulière d'atrophie musculaire progressive, souvent familiale débutant par les pieds et les jambes et atteignant plus tard les mains". Revue médicale . Paris . 6: 97--138 . 1886 .), and Howard Henry Tooth (1856--1925) ("The peroneal type of progressive muscular atrophy", dissertation, London, 1886 .) </P>

How did charcot marie tooth disease get its name