In this issue: Why is genetic testing for SDS important and how do I access it?
Welcome to our timely updates on all things SDS, Science, and Advocacy. We bring you a digest of recent scientific publications, conferences, and other newsworthy content - all relevant to SDS - with links to more details and learning opportunities. Are you interested in anything specific? Did we miss something? Let us know. Email genetics@SDSAlliance.org or message us on Facebook! This is all for you!
Spring into Action: Genes and Genetic Testing for SDS
On Rare Disease Day two weeks ago, we launched our "Spring into Action" campaign, with which we amplify the patient voice in SDS in order to improve patients' lives, be it through more focused, impactful research, community support, or advocacy.
Over the next few weeks and months, we will highlight multiple efforts, resources, and learning opportunities. Today, we bring you a summary of genes, genetic testing, and the importance of both in SDS.
What are genes?
Our bodies are composed of trillions of cells that have many different roles – to help us grow, digest food, protect us against infections, and more. These different tasks are controlled by a set of instructions known as genes. (We even have genes whose purpose is to protect us against cancer!) Genes are made up of DNA, which you inherit from your parents, and they determine things like your eye color, height, and even your risk for certain health conditions.
What are genetic mutations (i.e., variants)?
Sometimes there are mistakes in our genes, like a typo or error in an instruction manual or recipe book. These genetic mistakes are called mutations or variants. Shwachman-Diamond Syndrome (SDS) happens because of these genetic mistakes in certain genes including SBDS, EFL1, DNAJC21, and SRP54. These genetic mistakes are passed down from parents to kids and cause SDS.
Imagine if a sentence in a recipe book had a mistake, like telling you to turn off the oven to bake cookies. Then the cookies wouldn’t bake properly! Our cells work the same way. If there's a mistake in the genes that tell our cells what to do, our cells may have a difficult time functioning properly.
You can also watch our SDS Science Spotlight video on the Genetics of SDS to hear more about how these genetic mistakes (or mutations) contribute to the development of SDS.
What is genetic testing?
Genetic testing is the process of analyzing a gene (or more commonly, a set of genes) for these genetic mistakes that would result in SDS. Genetic testing is comparable to reading an instruction manual or recipe book very closely to identify any errors made during the writing process.
Why is genetic testing for SDS important?
Genetic testing for SDS helps your care team confirm a diagnosis of SDS and provide a clearer understanding of why you may be experiencing certain health issues. A genetic diagnosis of SDS can help guide your care team in making and following personalized treatment plans and surveillance guidelines to help you stay healthy!
What types of genetic testing are recommended for individuals with symptoms of SDS?
There are different kinds of genetic testing available for individuals who have a suspicion for SDS based on symptoms or health issues and/or a family history of SDS.
If we return to the instruction manual analogy when considering the different types of genetic testing, there are some genetic tests that only look for errors in specific sections of the instruction manual known to be associated with SDS. This type of genetic testing only looks at one or all of the known SDS/SDS-like genes, including SBDS, EFL1, DNAJC21, and/or SRP54.
There are other more thorough types of genetic testing that look for errors in the entire instruction manual, meaning all of the genes in your cells (over 20,000!) are analyzed. This kind of genetic testing can be costly and time-consuming but may provide an answer for some families as we learn more about the genetic cause(s) of SDS.
My care team has mentioned their concern for SDS, how do I access genetic testing?
If your care team has mentioned a concern for SDS, we encourage you to talk with them about your options for genetic counseling and testing. Genetic testing can be ordered by a healthcare provider such as a doctor or a genetic counselor. In the SDS community, physicians who order genetic testing for SDS frequently include primary care physicians, pediatricians, gastroenterologists, hematologists, oncologists, and many others.
For individuals in the United States, The National Society of Genetic Counselors has a Find a Genetic Counselor Tool available on their website to search for a genetic counselor local to you. We encourage you to choose the specialties of Cancer, Hematology, and/or Pediatrics to help you narrow your search for a genetic counselor.
If I have SDS myself, and my partner doesn't, can our kids get SDS?
The odds of your children getting SDS depends on your and your partner's genetic makeup. For example, let's consider SDS caused by mutations in the SBDS gene, which typically is inherited in an autosomal recessive pattern. A partner who doesn't have symptoms of SDS may be a carrier of one mutation in a gene that causes SDS or have no mutation at all. The partner with SDS will have two mutated versions of the gene, and no healthy copy. The odds of the children getting SDS will depends on all these factors and more, such as rare genetic events related to pseudogenes, for example. Check out the video embedded above. We covered the concept of pseudogenes in an earlier edition of the snapshots, and these may factor into the odds as well.
If you have a diagnosis of SDS and/or a family history of SDS, and are planning a pregnancy, you may also find it helpful to speak with a Prenatal Genetic Counselor to discuss what genetic testing might be available to help inform you and your partner on the chances of having a baby who also has SDS. For individuals in the United States, The National Society of Genetic Counselors has a Find a Genetic Counselor Tool available on their website to search for a genetic counselor local to you.
Stay tuned to our Science Snapshot series this Spring to learn more about genetic testing resources that may be helpful for your family!
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