What are genes and variants?

Genes tell the body how to develop and function. Humans have approximately 30,000 genes. A complete set of our genes is located in the nucleus (or center) of almost every cell in the body. Genes are organized on structures called chromosomes, and humans have 23 pairs of chromosomes. Chromosomes are made of DNA (deoxyribonucleic acid), which is a chemical arranged in a linear sequence. And genes are DNA sequences, which serve as templates to make proteins that carry out each gene’s function. Genetic testing is an analysis of the DNA sequence of a gene that looks for abnormal variations. Some variations may be harmful because they can disrupt the gene’s ability to make a functional protein. These harmful variations are called mutations.1,2

DNA in the body.

What is genetic counseling?

Genetic counseling is the process of helping people understand and adapt to the medical, psychological, and familial implications of inherited conditions.

  • This process includes:
    • Collecting personal and family histories to inform the individual of their genetic risk and chance of developing the condition
    • Educating about inheritance, testing, management, prevention, resources, and research
    • Counseling to promote informed choices and adaptation to the risk or condition

All participants in the ATLAS Study will receive genetic counseling and genetic testing of the SOD1 gene at no cost. Genetic counseling will occur before and after genetic testing (pre- and post-test). The genetic counseling appointments will be in person at the study center or conducted over the telephone or by teleconference. Some participants in the United States may have genetic counseling provided over the telephone by genetic counselors from InformedDNA.* The participant can invite additional family members or friends to join the appointment, if desired.

Participants can withdraw their consent for ATLAS participation after they meet with the genetic counseling provider (or at any point in the study) if they decide they no longer wish to proceed with genetic testing or study participation. The following lists are typically reviewed and discussed at the pre- and post-test presymptomatic genetic counseling appointments.

  • Pre-test genetic counseling appointment:
    • Collect the participant’s medical history and a detailed family history
    • Discuss the genetics of ALS, including what is currently known and what remains uncertain about the SOD1 gene, and the association of SOD1 variants with ALS risk
    • Explore the potential benefits, risks, and limitations of genetic testing
    • Help participants understand the potential social and psychological risks associated with learning one’s personal SOD1 gene variant genetic test result
    • Discuss the possible impact of genetic test results on personal health, insurance, and implications for family members
    • Discuss sample collection options for genetic testing, which may be performed at the study center or through at-home sample collection
      • For at-home sample collection, a blood draw technician working with the study will visit the participant’s home and then mail the blood sample to the lab for testing
      • Results are available approximately 10–21 days after sample collection
  • Post-test genetic counseling appointment:
    • Disclose and review the participant’s SOD1 genetic test result
    • Discuss the potential implications of the genetic test result for the participant and their family members
    • Help identify support resources for the participant or their family members2,3

Benefits, burdens, and risks of genetic testing.

Genetic testing isn’t right for everyone. A few of the general benefits and risks are listed below. The list is limited, and not all the points may apply to everyone. However, they might provide some useful things to think about when considering genetic testing. It is encouraged that individuals discuss this with their doctors and possibly family members.

  • Knowing the results of a genetic test may help individuals be more involved with their health and life planning, such as family decisions, participation in clinical trials, and other planning
  • The physical risks associated with genetic testing are very small; the test is done using a blood sample
  • Before choosing to undergo genetic testing, the individual should consider how the results could or may affect their family members and the possibility of genetic discrimination in employment and insurability for disability, health, and/or life insurance

There is no right or wrong answer regarding undergoing genetic testing – other than what the right answer is for the individual and their family.

Who receives genetic test results.

Genetic test results are sent to the genetic counseling provider and to the study investigator of the study center where the participant is enrolled. The genetic counseling provider will discuss the genetic test results with the participant.

Confidentiality.

No personal identifying information of individuals referred to the study or individuals participating in the study will be shared outside the study team and regulatory agencies.

References.

  1. ALS Association (n.d.). Genetics. www.als.org/research/research-we-fund/scientific-focus-areas/genetics.
  2. MedlinePlus (n.d.). Genetics. medlineplus.gov/genetics/.
  3. National Society of Genetic Counselors (n.d.). About genetic counseling. www.aboutgeneticcounselors.org/Genetic-Counseling.

*InformedDNA is an independent provider of genetic counseling services in the USA. The InformedDNA geneticists and genetic counselors are board-certified. Participants have the convenience of participating in private genetic counseling sessions via telephone. For more information, visit www.InformedDNA.com.