logo Click here for the MAMMAG Home Page Click here for the UC Irvine Home Page Click here for the School of Medicine Home Page
 
 
 
 

5006: VCP gene - Sequencing of exon 5

Order this test

Test Code Test Name Turnaround Blood Sample Tissue Sample CPT Codes 2015 CPT Codes 2013
5006 IBMPFD VCP (Valosin containing Protein) 3 weeks $340.00 $440.00 81403 81479
exon 5 Sequencing

Selecting the Appropriate Sample Type

VCP Inheritance and Genetics

Mutations in the Valosin Containing Protein (VCP) gene cause an autosomal dominant disorder called Inclusion Body Myopathy associated with Paget's Disease of Bone +/- Frontotemporal Dementia (IBMPFD). It is estimated that 80% of symptomatic people also have a parent with symptoms, 20% of IBMPFD occurs because of a new mutation or without recognized family history. Penetrance is almost complete (approximately 90%), but age of onset of symptoms varies significantly between individuals. Symptoms will typically be recognized by doctors in the 40s or 50s although subtle symptoms may be recognized by the patients as early as their 20s or 30s. Individuals in the same family may have different symptoms and different ages of onset even if they have the same VCP mutation.

VCP or p97, is the only gene known to cause IBMPFD, but other genes may be found in the future. VCP mutations will be found for approximately 70% of people who meet clinical criteria for IBMPFD. VCP is located at 9p13 - p12, and there is evidence that it is involved in a number of cellular activities including cell cycle control, membrane fusion, and the ubiquitin-proteasome mediated endoplasmic reticulum-associated degradation pathway.

Ordering the VCP test

There are a number of options to order genetic testing of VCP. Physicians can order full sequencing of the gene, or targeted sequencing of exons where mutations are most often found. Turnaround time is within 3 weeks for each tier of testing ordered. Blood samples are most often used for nuclear gene testing, but muscle or other tissue samples will be accepted if necessary.

Tiered Testing Options

5008 VCP whole gene sequencing Sequencing of all 17 exons of VCP
5006 VCP exon 5 sequencing 63% of identified mutations have been found in exon 5
5007 VCP exons 3, 5, 6, 7, 10 sequencing All 10 unique mutations identified to date are located in exons 3, 5, 6, 7, and 10 of the VCP gene

Clinical Features

People with IBMPFD may have one or a combination of the three main features. Symptoms may include:

  • Myopathy: Muscle disease is adult onset, progressive, and the proximal muscles are usually affected before the distal muscles in the legs and arms. It may clinically resemble limb-girdle (LG) or facio-scapulo-humeral (FSH) muscular dystrophy. Family studies have found myopathy in 87 - 92% of people with IBMPFD.
  • Paget’s disease of bone (PDB): Paget’s disease is caused by problems with bone turnover, meaning that there are irregularities in the way bone breaks itself down and replaces itself. Symptoms of PDB include bone pain, localized bone enlargement, deformation of the long bones, and deafness from eighth-nerve compression. Family studies have found PDB in 51-57% of people with IBMPFD, usually with an earlier onset (mean age of 42) than is seen with isolated PDB (mean age of 59 years in those without family history).
  • Frontotemporal dementia (FTD) that preserves memory but affects reasoning, personality, and language. In family studies approximately 30% of people with IBMPFD have FTD.

Approximately 12% of people with IBMPFD are affected with all three features listed above. 50% of affected people have two of the features, 30% have apparently isolated myopathy, and 8% have apparently isolated PDB or FTD.

IBMPFD Resources

  • IBMPFD Brochures 
    Educational Materials that discuss IBMPFD and VCP genetic testing are available for download below:
  • For more clinical information about IBMPFD, please visit GeneTests and OMIM.
  • Research Laboratory of Virginia Kimonis, MD
    Research studies may be available through the research laboratory of Virginia Kimonis, MD, MRCP. You can find the research laboratory website here or call 714-456-2942 for more information about research participation to help scientists learn more about IBMPFD and the VCP gene.
  • ibmpfd.com 
    David Sweetman, a patient advocate with IBMPFD, maintains a website: ibmpfd.com. The website offers a message board, contact information for research groups, and a variety of other useful information for patients, caregivers, and researchers.
  • Muscular Dystrophy Association 
    IBMPFD is not yet recognized by the Muscular Dystrophy Association (MDA); however, many MDA centers accept persons with IBMPFD to their programs. The muscle related symptoms and daily challenges are similar to those experienced by people with muscular dystrophy or IBM (Inclusion Body Myocitis), a disease that is recognized by MDA. Patients may wish to visit the MDA website or to call them at 1-800-FIGHT-MD (1-800-344-4863).
  • Genetic Counseling 
    Genetic Counseling is recommended to guide patients and their families through the process of deciding whether to have a genetic test and understanding the results. You can locate a genetics professional in your area through one of these organizations or ask your doctor for a referral: