Genetic Testing

​​Finding a VCP gene variant through genetic testing is the only conclusive way to establish an accurate diagnosis of VCP disease.

(Disclaimer:  Cure VCP Disease, Inc. is  providing the below information​ to the best of our knowledge.  The organization is not advocating any particular company or method. Consultation with a genetic counselor or clinical geneticist prior to and following testing is recommended.)

VCP Gene Testing Options:

There are a number of options for genetic testing of a VCP gene variant.  Physicians can order full sequencing of the VCP gene, or targeted sequencing of exons where mutations are most often found. Turnaround time is within 3 weeks for each tier of testing ordered. 

  1. Free Genetic Testing through Perkin Elmer: https://www.perkinelmergenomics.com/lanternproject/.  The VCP panel is available through the Limb Girdle Muscular Dystrophy link.

  2. Invitae offers their Detect Muscular Dystrophy panel free of charge for those that meet certain qualifications. The Comprehensive Neuromuscular Disorders panel includes the VCP gene.

  3. GeneDx includes the VCP gene in some of their panels. Type "VCP" in the search box at the top right to see a listing.

Purpose of VCP Genetic Testing:

A proper diagnosis allows for symptomatic individuals to receive needed help, support and treatment. An accurate diagnosis gives information and opportunities for:

  • Screening guidelines for potentially affected systems (e.g. echocardiograms, PDB evaluation) permitting earlier treatment of these conditions

  • Lifestyle changes for the patient (e.g. changes in diet, nutrition, and exercise)

  • Career and housing choices

  • The choice to participate in research and to learn more about VCP Disease

  • Accurate recurrence risk counseling or identification of at risk family members

  • Pre-symptomatic testing for family members who are at risk

  • Pre-implantation genetic diagnosis (PGD) in conjunction with in vitro fertilization (IVF) for families who wish to have only pregnancies that do not carry a familial VCP mutation

Risks of VCP Genetic Testing:

An individual should take into consideration social, financial, life insurance, and disability insurance implications prior to genetic testing. A genetic counselor can help guide a person through this decision and proper timing for a symptomatic individual.  As with other adult onset disorders, pre-symptomatic patients require psychological preparation before testing, including in depth discussion of their reasons for testing and how both positive and negative results would affect their lives. Discussing the implications of testing will allow the patient to make a fully informed decision about whether or not to proceed.

Genetic privacy and discrimination issues have been a large area of concern, especially among people seeking pre-symptomatic genetic testing. The passage of the Genetic Information Nondiscrimination Act (GINA) of 2008 now provides protection against health insurance and employment discrimination based on genetic information. However, this law does not cover life, disability, or long-term care insurance and does not apply to members of the military. It is also still relatively new and has not yet been tested in court, so the extent of GINA’s protection is still not well established. Patients should still think carefully about how their DNA test result might impact their employment and insurance. In addition, it is important to allow sufficient time before ordering the test for the patient to make any necessary financial or insurance arrangements.

Genetic Testing Considerations for at Risk Family Members:

Since VCP is autosomal dominant, a person has a 50% chance of inheriting VCP disease if they have one parent with a VCP gene variant, regardless of gender. 

  • Symptomatic individuals: In a family with an established diagnosis, it is appropriate to consider testing of symptomatic individuals regardless of age.

  • Asymptomatic at risk relatives:  Predictive testing for at risk relatives is possible once the pathogenic variant has been identified in an affected family member. A proper diagnosis prior to onset can allow for proper monitoring and lifestyle changes. Because of the individualized nature and risks of predictive testing, consultation with a genetic counselor or clinical geneticist prior to and following testing is recommended.

  • Minors:  It is not appropriate to test asymptomatic minors at risk for adult-onset conditions for which early treatment would have no beneficial effect on disease morbidity and mortality. Predictive genetic testing is considered inappropriate, primarily because it negates the autonomy of the child with no compelling benefit. Further, concern exists regarding the potential unhealthy adverse effects that such information may have on family dynamics, the risk of discrimination and stigmatization in the future, and the anxiety that such information may cause.

Resources:

Our medical advisors have offered to be resources to physicians and patients needing more information about genetic testing for VCP disease.

  • Virginia Kimonis, M.D., University of California, Irvine

  • Dr. Chris Weihl, M.D./Ph.D., Washington University, St. Louis