The Alnylam Act acute hepatic porphyrias program provides no-charge genetic testing for the acute hepatic porphyrias. For details on eligibility and ordering, please visit the Alnylam Act acute hepatic porphyrias page.
Understand the meaning behind common genetic testing terms:
Variant: a change in the sequence of the DNA that may or may not affect the function of the gene(s) or product(s). Variants can be pathogenic, likely pathogenic, benign, or have unknown significance.
- Pathogenic: Pathogenic variants (sometimes called mutations) are changes in your DNA that lead to a known health condition. If you have a pathogenic variant in your DNA, you will receive a positive test report.
- Likely pathogenic: Likely pathogenic variants (sometimes called mutations) are changes in your DNA that are expected to lead to a known health condition. If you have a likely pathogenic variant in your DNA, you will receive a positive test report.
- Benign: Everyone's DNA contains many variants, and most are benign. Benign variants are changes to the DNA that do not lead to known health conditions. Among other reasons, many of these variants are considered benign because the frequency of the variants in the general population is much higher than would be expected for a variant that could cause disease. Since there is no evidence that these variants are disease-causing, benign variants are not included in your test report and you will receive a negative test result if no other variants are identified.
- Variant of unknown significance (VUS): A variant of unknown significance (VUS) is a change in your DNA that has an uncertain or unknown impact on your health. If you have a VUS, you do not necessarily have an increased risk of developing a certain health condition. Over time, the scientific and medical community will identify new evidence about each particular VUS, and the classification of the variant may change from VUS to pathogenic, likely pathogenic, or benign. If a VUS in your sample is reclassified to pathogenic or likely pathogenic, Invitae will notify your clinician and issue an updated report.
Positive: If you test positive for a pathogenic or likely pathogenic variant, you have an increased risk of developing a disease. In most cases, there are medical management options available to help prevent disease or detect it at an earlier, more treatable stage. We strongly recommend that you speak with a licensed, board-certified genetic counselor to review your test result.
Negative: A negative result means that you do not have a disease-causing variant that is associated with an elevated risk for genetic disease. In most cases, increased screening and preventive measures will not be indicated for you.
Deletion or duplication: Deletions and duplications are large sections of DNA that are missing or extra. They can range in size from a small section within a gene to a large chunk containing multiple genes. Invitae’s tests include detection of deletions and duplications in most cases.
Next-generation sequencing: Invitae uses technology called next-generation sequencing (NGS) to determine the sequence of patients’ DNA. NGS allows multiple pieces of DNA to be sequenced at the same time, making it much quicker and less expensive than past methods of DNA sequencing. The data from NGS is analyzed to identify variants in your DNA that may increase your chance of developing certain health conditions.