How to make sense of your Genetic Test Results for Titin
Changes found in a gene are sometimes called mutations or variants. Some variants in a gene may lead to health problems, while others may not. Not all variants are equally problematic. Many truncating titin variants are clearly associated with a high risk of heart or muscle disease, and these are often classified as “pathogenic” or “likely-pathogenic” in the clinical genetic test report. On the other hand some variants are clearly not harmful and are classified as “benign” or “likely-benign”. Often however, there is insufficient information about variants to tell if they are harmful and these are classified as “variants of uncertain significance” (VUS or VOUS). These variants may need follow up by experts.
There are many great doctors, researchers and clinicians working to discover which VUSs cause disease and which do not.
Interpreting Titin genetic testing results can be tricky. One reason for this is that Titin is such a huge gene. Titin’s size matters for several reasons: one is that until recently, scientists did not have the technology to tackle such a giant gene. New tools have allowed researchers to learn more about Titin, and doctors are beginning to reveal what kind of changes in Titin are disease-causing and which are not. The second reason is that because Titin is so large and has so many parts (known as exomes), there are many chances for variation.
VUS, now what?
So, if you have been diagnosed with a VUS, how do you figure out if it is the cause of your condition or not? Here are a few recommendations:
Additional testing options:
– If one or two disease causing variants were identified in the same gene, testing is recommended for other relatives who might be at risk to be affected or a carrier. People who have single variants in the Titin gene may be at risk for heart problems and should have a heart check up, even if s/he feels well.
– If two disease causing variants are identified in the same gene, testing of parents or other relatives may be recommended to determine whether each parent carries one of the identified variants.
– For variants of unknown significance, other kinds of clinical testing might be necessary. These tests may provide additional information to aid in the reclassification of a VUS and/or help support or refute the diagnosis of a specific disorder. For Titin, this might include medical tests such as:
- Heart function tests such as EKG and echocardiogram
- Creatine phosphokinase (CPK) blood levels
- Neurological examination
- Muscle imaging including: ultrasound or MRI that can show patterns of weakness
- Breathing tests (including a sleep study and pulmonary function test that measures breathing capacity and cough strength)
Genetic Counseling
Consider meeting with a genetic counselor. You can find a genetic counselor through the National Society of Genetic Counselors, which offers a searchable directory of genetic counselors in the United States and Canada. You can search for counselors who offer in-person or telehealth appointments. Ideally, look for a genetic counselor with experience in neuromuscular conditions or inherited heart conditions, depending on your diagnosis or family history.
Or for help finding genetic counseling resources for neuromuscular conditions in the United States, contact the Muscular Dystrophy Association (MDA) Resource Center at 1-833-ASK-MDA1 (1-833-275-6321) or email ResourceCenter@mdausa.org. MDA can help connect families with MDA care centers that often include genetic counseling along with other resources.
Or you can also search Orphanet’s directory of expert centres to find specialty clinics for rare diseases, including clinics offering genetic counseling.
Genetic Testing Options and Resources
Genetic testing can help identify the cause of an inherited muscle or heart condition and provide important information for individuals and their families. A genetic counselor or healthcare professional can help you understand which tests may be appropriate.
The following resources offer genetic testing or assistance accessing testing. Some programs offer no-cost testing for eligible individuals, while others accept insurance or offer self-pay options. Availability and eligibility may change.
Genetic testing for muscle conditions
- Detect Muscular Dystrophy Program (Invitae/Labcorp Genetics): Offers no-cost genetic testing for eligible individuals in the United States with suspected muscular dystrophy. The program is offered in partnership with the Muscular Dystrophy Association (MDA) and provides several genetic testing panels, including neuromuscular testing.
Genetic testing for heart conditions
- Heartgene (formerly Everygene): Offers no-cost genetic testing for eligible adults with cardiomyopathy or certain inherited heart rhythm conditions in the United States. Testing is not currently available in New York State.
- Genetic Cardiomyopathy Awareness Consortium (GCAC): Provides information about genetic testing options for people with cardiomyopathy and their families, including no-cost testing programs and insurance-based options.
Additional genetic testing options
- Invitae/Labcorp Genetics: Offers clinical genetic testing for inherited muscle and heart conditions. Insurance coverage, financial assistance, and self-pay options may be available.
- GeneDx and Genome Medical: Offer access to genetic testing and virtual genetic counseling, particularly for children with suspected genetic conditions. Insurance coverage and financial assistance may be available.
Before pursuing genetic testing: Talk with your healthcare team or a genetic counselor about which test is most appropriate, whether it includes the TTN gene, what the results may tell you, and any potential costs. Some sponsored testing programs also have specific policies about sharing de-identified genetic information with research or industry partners.
For help with confirming a titin genetic diagnosis contact:
Prof Bjarne Udd, MD, PhD
Tampere Neuromuscular Center
Folkhälsan Research Institute, Helsinki bjarne.udd@netikka.fi
Read about genetic information about recessive titinopathy here.
Geneticists can check titin variants in the TITINdb here.
Last reviewed: October 2026. Please visit each program’s website for current eligibility and availability.