When and Where?

     Charcot-Marie-Tooth disorder, or CMT for short, is inherited by one's parents.  This was discovered in the 1930's by geneticist Calvin Bridges.  In 1991, bad news turned to worse news when Dr. James Lupski, professor at the Baylor College of Medicine, discovered that as the disease is passed down through generations, it becomes more severe.
     CMT occurs when a band on chromosome 17 is duplicated.  During S phase in Interphase, DNA is replicated and this is when the duplication occurs.  However, this disorder is not so simple.  As Dr. Lupski discovered in 1991, if someone with this duplication reproduces, their child will have a triplication of the band and therefore inherit a more severe case of the disease.
     Dr. Lupski and his colleague, Dr. Lui, believe that a triplication would continue onto the next offspring, as the duplication did, but it has not been tested because of how severe the effects of the triplicated CMT is.
     There a several variations of the CMT disease, but all forms (tested by doctors that did not know who had what version of CMT) held the pattern that duplications increased to triplications in the next generation.