The short, educational videos linked below include information about genetics, genetic testing, and types of results and findings:
The content of these videos was originally developed at Columbia University Irving Medical Center and was modified by the RADIANT team with permission to reflect information most relevant to the RADIANT study.
There are several different types of genetic testing performed in RADIANT, which are summarized below. If you participate in the RADIANT study, you may have one or more of these types of genetic testing done in the study. This depends on your medical history and what information the study team needs to better understand your or your family member’s diabetes.
DNA will be extracted from your blood sample and your genome will be sequenced using next-generation sequencing technology.
Your genome sequence will first be evaluated by a clinical laboratory (CLIA/CAP accredited) to see if you have a known form of genetic diabetes, such as maturity onset diabetes of the young (MODY).
Only genetic changes, or "variants", that are known to be disease-causing will be reported by the laboratory (i.e., pathogenic and likely pathogenic variants). Variants of unknown clinical significance will not be reported by the laboratory. Additionally, specific types of genetic variants, such as chromosomal rearrangements, large deletions or duplications, and triplet repeat expansions, will not be reported.
When you consent for this part of the study, you can choose whether you want to receive your genetic results for genes known to cause diabetes. The genes we test that are known to cause diabetes are listed here: RADIANT Genetic Testing Diabetes Gene List
You can also choose whether you want to receive your genetic results for genes that greatly increase your chance of developing some types of cancer or heart disease. These are termed "secondary findings" by the American College of Medical Genetics and Genomics (ACMG). The list of genes can be found in a publication by Miller et al. (PMID: 34012068): https://www.nature.com/articles/s41436-021-01172-3.
Importantly, if you have a personal or family history of a secondary findings disease, your healthcare provider may still recommend a clinical genetic test outside of RADIANT, as it may analyze more or different genes than are present on the ACMG list RADIANT is using.
Note regarding RADIANT participants under 18 years old: If a RADIANT participant is under age 18, only disease-causing variants in genes related to disorders that have a childhood onset will be reported. Then, if the participant turns 18 years old during the course of the study, they can reconsent to receive information on conditions with adult onset.
If your diabetes is not explained by the clinical genome analysis, your genome sequence will be evaluated by the research team in conjunction with your clinical information. For novel genetic variants that may be involved in your diabetes, this information will be used to determine what other research procedures will be conducted and which, if any, family members might be invited to participate either in the full study or for Sanger sequencing of a variant(s) of interest (see #4). If during the period the study is funded, a variant found at this stage is later definitively confirmed to be the cause of your diabetes, we will tell you about this variant if you chose to receive your genetic testing results.
If a genetic variant(s) is found in a RADIANT study participant that the research team believes may be the cause of the participant’s diabetes, family members may be invited to undergo Sanger sequencing for the variant(s) of interest to assess whether the variant(s) follows the pattern of diabetes in the family. Some family members may be invited to participate in the full study if more extensive characterization is determined to be useful by the research team.
Mitochondrial sequencing will be performed for some participants who may have a possible mitochondrial DNA variant causing their atypical diabetes.
RNA sequencing will be performed for some participants to help the research team’s interpretation of the participant’s genome sequencing.
If you have any questions, please contact us.