Part 2 The Youngtimers Guide to Genetic Testing

Many people worry about discrimination based on their genetic test results, and rightly so. With the advent of digital patient records, informed patients should make every effort to protect their and their families’ privacy. In 2008, the US Congress enacted the Genetic Information Nondiscrimination Act (GINA), to protect individuals against discrimination by their health insurance provider or employer. However, GINA does not apply to long-term care, disability, or life insurance providers.

Thus, it is important to obtain these policies before undergoing genetic testing:

Consider obtaining life insurance
Consider obtaining long-term care insurance
If you can, obtain a copy of your parent’s or family member’s positive test result (i.e. the genetic testing report they received listing the nucleotide or amino acid change; it should also have their accession or testing ID number). If you do not have this information, see below.
Begin setting up a support system. Many sites require that you have a support person with you, so you should decide who this person will be. Counselors recommend it be someone who is not at-risk of inheriting a DIAD mutation. Getting tested can be an emotional rollercoaster and having 1-2 people (other than your partner or support person) to talk to about this process can be very helpful. It may also be helpful for the partner/spouse to set up a support system as well.

I’m ready to get tested

What now?

Individuals who have undergone testing have recommended telling close friends that you were undergoing the process, but to do so without giving away specific dates of appointments. That way you don’t feel pressure to respond to calls or texts, and instead have an opportunity to process your results on your own before reaching out to others. It can often be hard to discuss these with family (as everyone’s perspective and way of dealing with the disease is different). In those cases, at-risk individuals also reached out to a fellow DIAD family member who served as a support person.

Who to tell?

Here are some important questions to ask or things to consider when looking for a genetic counselor:

They have previous experience working with dominantly inherited Alzheimer’s disease or Huntington’s disease.
They were recommended/found through the National Society of Genetic Counselors or your local Alzheimer’s Disease Research Center.
They follow the Huntington’s Disease genetic testing protocol.
They are aware of your privacy concerns and are willing to take steps to keep your genetic information outside of your medical records: i.e. they are willing to keep you off their electronic records and/or only keep you in their paper files. They possibility allow you to test under a pseudonym.

Find the right genetic counselor for you

General information:

The sessions consist of one visit with a physician to order the test (not needed if the genetic counselor works with an MD who can order the test or if the counselor is able to order the test), one visit for a pre-testing genetic counselor session and one visit for a post-testing genetic counselor session. Please note that some genetic counseling sites will also require a psychological evaluation prior to testing.

No. of sessions: ~2-3 sessions
Avg. length of a session: 30 min – 1.5 hr
Type of tissue collection: blood, saliva, cheek swab
Avg. wait time before receiving result: 1 – 3 months

What happens in the first (or pre-testing) session with a genetic counselor:

The pre-test genetic counseling session should review the patient’s personal and family history, and inform the patient of the benefits, risks, and limitations of undergoing genetic testing. In session 1, the genetic counselor will discuss the inheritance of the genetic mutation of interest. They should help answer any questions you may have regarding genetics, including: 1) what is an autosomal dominant disease, 2) how are genetic mutations passed on in the family, 3) what are the chances of getting the disease, 4) what are the chances of offspring or children getting the disease, etc. They will draw a family tree which includes who has been affected by the disease and whether or not these individuals have been tested. This is also when you will provide a report of any family member’s genetic testing results, if you have one.

During this session, genetic counselors will also help walk you through potential scenarios and your responses to a negative and positive test result. This is your change to discuss and think about what it would be like to find out your were positive for the mutation or negative for the mutation, and how would it affect your mental state/feelings, life plans/goals, spouse, relationships with others, family relations, financial matters, reproductive options, etc.

In the last part of session 1, the genetic counselor will ask if you are ready to provide tissue for testing. If you agree to proceed, you’ll need to work out how the payments will be made. Make sure that if you are working under a pseudonym, you either bring cash or a cashier’s check to the appointment. After that, blood, saliva, or cheek swabs will be taken and then placed in an envelope to send to the test facility. This is a good time to work out any more logistics with your counselor (i.e. how long you’ll have to wait until your result is ready, how long they recommend you wait, whether you prefer them to wait to open your result/envelope until you are there, how you prefer to be contacted, etc.). This is your chance to let the genetic counselor know your preferences for receiving this important news.

For both sessions, you may be asked to bring in a support person. They often require or recommend that this person not also be at-risk for the same gene (i.e. a sibling). If you intend on bringing a spouse or partner, the counselor should help prepare them for the result as well. Some spouses have not had as much time to deal with the social and psychological consequences of hearing a loved ones’ result, so it may be helpful to speak with a loved one about this earlier.

What happens in the second (or post-testing) session with a genetic counselor:

In session 2, the genetic counselor will ask whether you are ready to hear your result. Other at-risk individuals recommend that you not try to “read” into your genetic counselor’s behavior, it will in no way reflect your genetic status. Once you are ready, the counselor will reveal your test results, in some cases this is opening an envelope. There have been many cases where individuals decide to wait to hear their results, so there is no pressure to do it any sooner than when you are ready. Either way, the individual should seek a mental health professional or psychologist to help digest the results on a more long-term timeline than the genetic counselor can provide.

What should I expect when going through genetic testing?

Cost: $200 - $2,000

These numbers are according to the NIH Genetics Home Reference. If you break down the costs, it is ~$250-$450 for the genetic test (usually with Invitae, Prevention Genetics, or Athena) and ~$250-$350 per genetic counselor session. If you are enrolled in the DIAN Observational study or the DIAN-TU clinical trial, these costs will be covered. Insurance may cover some/all of these costs; however if you wish to be tested under a pseudonym, you may be required to pay out of pocket for some of these services.

What are the costs associated with genetic testing?

Transient increased anxiety and/or depression (extreme and catastrophic events have been reported, but are rare)
Improved understanding and knowledge for assisting future decisions
Heightened awareness of genetic status, disease stigmatization, and possible discrimination
Socioeconomic issues related to the need for long-term follow up of individuals with positive result
Survivor guilt

What are some consequences I can expect following genetic testing?

The genetic counselor or ordering MD should request panel genetic testing. This consists of testing all three genes’ (APP, PSEN1 and PSEN2) sequences entirely to determine if a DIAD-causing mutation is present. Panel testing can be 2-3 times more expensive than targeted testing of a specific gene and mutation. If possible, it is best to be tested at the same lab at which a relative with a positive result was tested, as the lab can compare your results with your relatives.

What if I don’t have my parent’s/family member’s genetic information?

The presence of a mutation does not always result in disease – the existence of escapees:

Most studies have shown that a person’s age of onset for developing disease is very close to the age in which their previous family members starting showing symptoms of the disease. For example, if the father developed Alzheimer’s at 45 years of age then the son who tested positive would likely develop the disease between 42-48 years of age. However, there have been instances where individuals test positive for a mutation but are 10-20 years past the age of onset of their parent and have still not developed the disease. Current studies are underway to determine how this occurs in these individuals. The existence of these individuals, however, means that if an individual tests positive for a disease-causing mutation, they do not have a 100% chance of developing disease, but rather a 99.5% chance.

What are some caveats and other considerations of genetic testing I should be aware of?

Many genetic testing companies are offering consumer genetic testing (i.e. 23andme), and initially it can seem less costly and more hassle-free compared to the traditional genetic testing route. However, individuals who are at-risk of DIAD should be careful when considering these tests. A recent article in the NY Times revealed that a commercial genetic test misdiagnosed a man with a PSEN1 mutation with no family history of the disease. He found the results disturbing. He then tested with another company and no mutation was found. This story should serve as a lesson for consumer genetic testing, as these tests are not FDA approved for testing mutations that cause genetic neurological disorders and often (as illustrated in this story) have poor accuracy. Here is a link to the NY Times article 23andMe Said He Would Lose His Mind. Ancestry Said the Opposite. Which Was Right

Part 2

The Youngtimers Guide to Genetic Testing