Testing Methodology & Limitations
Episona uses Illumina’s 450K Human Methylation array to measure the DNA methylation level at more than 480,000 locations across your genome. We then compare the values to a reference panel collected from more than 150 known-fertile donors to identify locations where your epigenetic pattern differs from theirs. Because everybody will have some differences, even known-fertile donors, we filter this set to include only those differences which we see consistently in men struggling to conceive naturally, or with consistent failure of assisted reproductive technologies (ART). Most known-fertile donors have a small number of such differences, while those struggling to conceive tend to have more. In addition to the differences we detected in your epigenome, we show you how many differences we generally detect in each group, as well as how strongly each difference seems to be associated with reduced chances of conception or positive outcome of ART. In many cases, there is existing scientific literature suggesting a likely-affected gene is involved in fertility or embryo development – when we are aware of it, we highlight this literature for you.
The technology we use allows us to profile more than 480,000 methylation loci across the human genome. However, there are more than 27 million loci, the majority of which we cannot interrogate at this time. The nature of DNA methylation is such that one locus in a region is often representative of others in the same region, so our sample of 480,000 gives a good overview of your epigenome. However, it is possible that you have epigenetic abnormalities at loci which we cannot investigate with our current technology and as such we would be unable to report to you.
We associate particular loci with genes based on their proximity: if the locus is within a gene, or very close by, we consider it to be associated with regulation of that gene. This is likely to be a good proxy, but we do not have sufficient information to confirm these relationships for every gene. In addition, some loci are sufficiently distant from any known gene that we label them as ‘intergenic’. It is possible that the three-dimensional arrangement brings these loci into close proximity of gene which they are then involved in regulating, but we are unable to determine such interactions at this time.
When determining if your epigenetic pattern at a particular locus is different from expected, we look for fairly large changes. Even if we report no abnormalities at a locus, you may still have subtle changes that are clinically relevant. As we collect more data we will be able to more reliably detect smaller, relevant differences.
This test cannot tell you whether you are infertile or not. Rather, it determines whether you have any markers that we have seen associated with decreased chances of conception in other patients. You will need to discuss with your physician whether your specific results warrant adjusting your treatment plan.
Episona, in partnership with the National Genetic Institute (NGI), uses several safeguards to avoid any technical errors, including barcode scanning throughout several steps of the analytical process. Episona is not responsible for any errors in specimen collection, transportation, and any errors occurring prior to the receipt of the sample at our laboratory. Due to the complexity of molecular diagnostic testing, errors may rarely occur due to sample mix-up, DNA contamination, or other laboratory operational errors. In addition, poor DNA sample quality or quantity may limit the accuracy of results.
All risk estimation is approximate and is based on prior cohorts that have been analyzed previously. An elevated risk of male factor infertility or poor embryo quality is not a diagnosis. Your actual chances of becoming pregnant may be different based on other genetic, epigenetic, lifestyle, or other factors.