6602: Genetics of Charcot Marie Tooth Disease

Status: Recruiting

Study Summary

Please Note: The Rare Diseases Clinical Research Network will make every effort to enroll all the patients we can, but we cannot make any guarantees that we will be able to enroll everyone in a particular study who wants to participate.


Charcot Marie Tooth disease (CMT) is an umbrella term that covers any inherited peripheral neuropathy. People with CMT have a problem with the nerves that go to the feet and hands that cause muscle and sensation loss, as well as difficulty with balance. There are two aims of this study: finding genetic modifiers for CMT1A, and finding new genes that cause CMT.

All people with CMT1A have the same duplication of the PMP22 gene. However, the symptoms that a person with CMT1A experiences can range from mild to severe. We are looking at the DNA and impairment of 1000 people to see if we can find other genetic causes that modify their CMT1A symptoms.

While many of the genes that cause CMT when mutated have been discovered, there are still many types of CMT for which the genetic cause is unknown. We are looking at small families who have forms of CMT that have not been identified by genetic testing to see if we can find the cause for their CMT.

 The research questions are:

  1. Are their genes that influence the symptoms of CMT1A?
  2. Can we identify new causes of CMT using small families with an unknown cause to their CMT?

About this Study

This is a study where we are collecting DNA from subjects once. We are looking to collect DNA and clinical information (as part of study 6601) on 1000 patients with CMT1A. You may be enrolled in study 6601 for an extended period of time, but the involvement for this study (6602) is a one time event. For small families (about 3 people) with unidentified forms of CMT, we will be enrolling 20 families. This is also a one time event. Enrollment includes entry into study 6601, and agreement to take part in 6602. For this study, we require a blood draw, where three tubes of blood will be taken.

Targeted Enrollment

To be eligible to participate, you must:

For the CMT1A Gene Modifier Study:
  • Have genetically confirmed CMT1A, or have a first or second degree family member who has genetically confirmed CMT1A and have nerve conduction velocities in the demyelinating range.
For the New Causes of CMT Project:
  • You have a neuropathy on nerve conduction studies or a clinically diagnosed genetic neuropathy AND
  • You or a first or second degree family member have had negative genetic testing for MFN2 if you have an axonal form of CMT (nerve conductions greater than 38 m/s in the arms), or negative genetic testing for PMP22 duplication, deletion, sequencing, MPZ, and GJB1 if a demyelinating form of CMT is present (38 m/s) AND
  • More than one additional family member is also willing to participate. One family member must be at least a second degree relative of one of the other participants (grandparent, uncle, aunt, niece, nephew, or half-sibling). Only one family member can be a first degree relative (parent, child, sibling).
    • Participation involves the other family members also agreeing to participate, enrolling in study 6601 – Natural History Evaluation of Charcot Marie Tooth disease, and provided a blood sample for DNA extraction.

You are not eligible to participate if:

  • You have a known neuropathy from a non-genetic source, such as chemotherapies, diabetes, or alcohol.
  • For the New Causes of CMT study, only full families of at least 3 people who match the inclusion criteria will be eligible.
  • For the New Causes of CMT study, if a known genetic cause of the CMT in the family has been found, that family is not eligible.

How to participate

In order to participate in a study, you must personally contact the study coordinator of any of the participating institutions by phone or by e-mail. Please use the information below to inquire about participation.

United States


  • Cedars-Sinai Medical Center, Los Angeles
    PI: Richard Lewis, MD
    Contact: Tara Jones, MS, LCGC
    Phone: 310-423-4268
    E-mail: tara.jones@cshs.org
  • Stanford University, Palo Alto
    PI: John Day, MD, PhD
    Contact: Carly E. Siskind, MS, CGC
    Phone: 650-721-5588
    E-mail: csiskind@stanfordmed.org



  • Nemours Children's Clinic*, Orlando
    PI: Richard Finkel, MD
    Contact: Aiza Rodriguez
    Phone: 407-650-7192
    E-mail: aixa.rodriguez@nemours.org

    *Note: This location is enrolling up to age 18 only
  • University of Miami
    PI: Mario Saporta, MD, PhD
    Contact: Lisa Abreu, MPH
    Phone: 305-243-2550
    E-mail: labreu@med.miami.edu


  • University of Iowa, Iowa City
    PI: Michael Shy, MD
    Contact: Nicole Kressin, RN, MSN
    Phone: 319-678-8596
    E-mail: nicole-kressin@uiowa.edu


  • Johns Hopkins University, Baltimore
    PI: Thomas Lloyd MD, PhD 
    Contact: Eun Park
    Phone: 410-955-7487
    E-mail: epark47@jhmi.edu


  • Massachusetts General Hospital, Boston
    PI: Reza Seyedsadjadi, MD
    Contact: Natalie Grant
    Phone: 617-643-3799
    E-mail: nrgrant@mgh.harvard.edu


  • University of Minnesota
    PI:  David Walk, MD
    Contact: Krista Mullen
    Phone: 612-626-5153
    E-mail: ness0153@umn.edu

New York


  • Children's Hospital of Philadelphia
    PI: Sabrina Yum, MD
    Office: 215-590-1719
    E-mail: Yums@email.chop.edu
  • University of Pennsylvania, Philadelphia
    PI: Steven Scherer, MD, PhD
    Contact: Diana Lee
    Phone: 215-573-4454
    E-mail: diana.lee@uphs.upenn.edu



  • The Children's Hospital at Westmead, Sydney, NSW
    PI: Joshua Burns, PhD
    Contact: Gabrielle Donlevy, Study Coordinator
    Phone: +61 2 9845 1328
    E-mail: gabrielle.donlevy@health.nsw.gov.au 


  • C. Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan
    PI: Davide Pareyson
    Co-PI: Isabella Moroni, MD
    Sub-Investigator: Chiara Pisciotta, MD, PhD
    Contact: Daniela Calabrese
    Phone: (+39) 02-2394.3001
    E-mail: Daniela.Calabrese@istituto-besta.it

United Kingdom

  • National Hospital of Neurology and Neurosurgery, Queens Square
    PI: Mary Reilly, MD
    Contact: Mariola Skorupinska
    Phone: 0044 203 108 7544
    E-mail: Mariola.Skorupinska@uclh.nhs.uk 

Learn More

What is CMT?