NCT01193075 · Michael Shy
Natural History Evaluation of Charcot Marie Tooth Disease (CMT) Types CMT1B, CMT2A, CMT4A, CMT4C, and Others
(INC-6601)
What this study is about
This is an observational longitudinal study to determine the natural history and genotype-phenotype correlations of disease causing mutations in Charcot Marie Tooth disease (CMT) type 1B (CMT1B), 2A (CMT2A), 4A (CMT4A), and 4C (CMT4C).
View original scientific description
This is an observational longitudinal study to determine the natural history and genotype-phenotype correlations of disease causing mutations in Charcot Marie Tooth disease (CMT) type 1B (CMT1B), 2A (CMT2A), 4A (CMT4A), and 4C (CMT4C).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- All patients must be seen in-person at a participating center for the initial visit. Inclusion Criteria - patients with CMT (all subtypes)
- Patient has documented, pathogenic or likely pathogenic CMT-causing variant(s) OR
- Patient has a first- or second-degree family member (parent, child, sibling, half-sibling, aunt, uncle, grandparent, or grandchild) with a documented pathogenic or likely pathogenic CMT-causing variant AND a clear link between that family member and the affected patient AND a phenotype consistent with the diagnosis i. A clear link is necessary for a second-degree relative. For example, if a grandparent is affected and has a pathogenic or likely pathogenic variant, and the parent does not have any signs, symptoms, or electrophysiology consistent with the diagnosis, there is no clear link unless the parent has also been found to have the pathogenic or likely pathogenic variant such as in cases with reduced penetrance ii. In cases where clear links are not available, genetic testing is required for the patient or the family member who is not clearly affected.
- Patients who have a variant of uncertain significance, as determined by the laboratory performing the testing may still be included if one of the following circumstances applies: i. Variant is categorized as pathogenic or likely pathogenic per the ACMG variant interpretation guidelines. \[80, 81\] ii. Variant has been found in multiple affected people in a family and has not been found in unaffected family members. (Note - both affected and unaffected family members must be tested in this situation to be included). iii. The principal investigator and the site investigator agree that the variant(s) is (are) most likely pathogenic.
- Patients whose clinical presentation is suggestive of CMT, but CMT type and variant are unknown will be characterized by the following categories:
- Nerve conduction velocities: demyelinating, axonal, intermediate
- Inheritance: dominant, recessive, X-linked, or unknown
- Patient or patient's legally authorized representative has understood and signed an IRB approved consent form for the study. Teenagers (age 13 - 17 years) and cognitively impaired adults who are able to read and write must sign an assent form (depending on local ethics committee requirements). Inclusion Criteria - Controls
- Person does not have a peripheral neuropathy, as determined by the investigator.
- Person has understood and signed an IRB approved consent form for the study. Teenagers (age 13-17 years) must sign an assent form (depending on local ethics committee requirements).
Exclusion criteria
- Patient has a variant of uncertain significance that cannot be further classified following methods listed in the Inclusion Criteria.
- Patient does not wish to be a part of the study or has not signed an informed consent form.
- Patient is deemed inappropriate by the Site PI.
Where
- Los Angeles, California
- Palo Alto, California
- Aurora, Colorado
- Hartford, Connecticut
- Washington D.C., District of Columbia
- Miami, Florida
- Orlando, Florida
- Iowa City, Iowa
- Baltimore, Maryland
- Boston, Massachusetts
- Ann Arbor, Michigan
- Minneapolis, Minnesota
And 4 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 7, 2025 · Source of record for eligibility and locations