630
edits
Changes
Jump to navigation
Jump to search
Line 2:
Line 2: + + + + + + + + + + + + + + − === Micro array testing === − === Whole exome/genome testing ===+ + + + + + + + + + + + + + + +
started fleshing out page
== Genetic testing providers ==
== Genetic testing providers ==
A number of commerical providers offer direct to consumer (DTC) genetic testing using different testing approaches.
=== Micro-array testing ===
Genetic testing based on micro-array technology is still the most widely used and offered form of DTC genetic testing due to the comparatively low cost of performing these tests. They analyze the genome for a wide array of different known genetic variants (between 300,000 and 700,000 variants depending on the provider). These variants are selected to help understand a person's ancestry and/or health, depending on the provider chosen.
Besides the raw testing results, providers deliver varying kinds of analyses. Virtually all DTC providers deliver ancestry results, based both on public reference populations as well as other customers of the given provider. Some providers like 23andMe additionally deliver results on human traits (also called ''phenotypes''). Some additionally offer health or well-being related predictions.
Common providers:
* 23andMe
* AncestryDNA
* FamilyTreeDNA
* MyHeritage
=== Whole exome/genome testing ===
{{stub}}
{{stub}}
Whole exome sequencing analyses the DNA that encodes all ~17,000 proteins that the human genome encodes. Unlike micro-array based methods (see above), this allows to find novel variants that have not previously been described. While exome sequencing can provide a more detailed analyses of the protein-coding regions of the human genome, it is important to keep in mind that only ~2% of the human genome actually encode for proteins, leaving 98% of the DNA unanalysed. In contrast, the thousands of variations used in micro-arrays fall both within and outside of protein-coding regions.
Whole genome sequencing analyses nearly all of the human genome. Consequentially it is also the most expensive way to get DNA testing done. Prices can vary both between sequencing providers as well as ''sequencing depth'', which is a proxy for how well and accurate the sequencing is. Generally, the larger the sequencing depth the higher the cost but also the possibility to reliably detect variants.
Common providers:
* to be filled
=== Limitations ===
=== Limitations ===
There are a number of limitations to DTC genetic testing: Most DTC genetic testing offers are not validated for clinical use and are not reviewed by the ''Food and Drug Administration'' in the US (or equivalent bodies in other countries), as such they are not designed to deliver medical advice. Additionally, some studies have found excessive false-positive rates in DTC genetic testing (up to 40% for some variants)<ref>https://www.nature.com/articles/gim201838</ref>.
DTC genetic tests are not generally available everywhere, as some countries (in particular in Europe, e.g. France or Germany) do not allow for genetic testing without a prescription by a medical doctor. Regardless of this, for some of those countries US providers offer testing by shipping sample collection kits into these countries while doing the actual sample processing back in the US.
== Genetic testing interpretation ==
== Genetic testing interpretation ==
While most DTC testing providers deliver their own interpretations of the results of the genetic test, there is a growing body of third-party tools that can use the raw data generated by DTC providers to deliver enhanced report
Tools:
* [https://genevieve.herokuapp.com/ Genevieve], uses the ClinVar database to deliver insights
* [https://www.snpedia.com/index.php/SNPedia SNPedia] / [https://promethease.com/ Promethease], makes use of the crowdsourced literature database of ''SNPedia''
* [https://www.ebi.ac.uk/gwas/ GWAS catalog], a catalog of published ''genome-wide association studies'' to look up impact of individual variants
* [http://myvariant.info/ MyVariant], an API that aggregates raw data for interpretation from a variety of sources
== References ==
== References ==