December 6 2013: Pending an FDA decision, 23andMe no longer offers new customers access to health reports. Customers who received their health information prior to November 22, 2013 will still be able to see their health reports, but those who purchased after that time will only receive their ancestry information as well as access to their uninterpreted raw data. These new customers may receive health reports in the future dependent on FDA marketing authorization.
Our service analyzes your DNA at specific points throughout your genome where single letters of the genetic sequence have been shown to differ among individuals. Ongoing research is linking these one-letter variations - known as single nucleotide polymorphisms, or SNPs - to many different traits and conditions.
However, there are many genetic conditions for which the 23andMe service does not provide health reports, including those in the following categories:
Trisomies and copy number variations
The presence of three or more chromosomes, rather than the usual pair; includes Down syndrome (trisomy 21), and Klinefelter syndrome (XXY).
When a trisomy is present, our algorithms report a genotype (consisting of two bases out of A, C, T, or G) for each position analyzed on the chromosome, but the genotype may reflect any two bases from the three chromosomes that are present. Our algorithms cannot reliably determine from the raw genotype data whether three chromosomes are indeed present. "No Calls" may happen more frequently for markers in regions affected by copy number variation, but "No Calls" may also occur for other reasons.
Trinucleotide repeat disorders
Disorders defined by the presence of an abnormal and unstable expansion of DNA; includes Huntington's Disease and Fragile X syndrome.
The genotyping platform 23andMe uses cannot test for trinucleotide repeat disorders with our SNP chip. The change that occurs is not a SNP (single nucleotide polymorphism), but a chunk of DNA that is repeated many times. Trinucleotide repeat disorders are caused by the length of a repeated section of a gene exceeding a normal range. As it is not related to SNP mutations, there is nothing relevant to the repeated section(s) in your raw data.
Repeats, insertions, or deletions
Resulting from the addition or loss of genetic material; includes Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA).
As our technology is not designed to analyze for repeated, inserted, inverted or deleted segments of DNA, in most cases we cannot provide information about copy number or other genetic features that are related to the number or order of base pairs present.
In addition to those listed above, at this time 23andMe does not provide health reports related to the following conditions:
Lynch syndrome (HNPCC), familial adenomatous polyposis (FAP), or other familial cancer syndromes
CYP2D6 and certain HLA alleles
Copy number variations (CNVs) or mosaicism
Comprehensive BRCA 1/2 or MTHFR analysis; details on these reports can be found in our BRCA and MTHFR help articles.
It is possible that we may be able to report on some of these conditions in the future as we learn more about the genetic markers analyzed by our current technology or develop new DNA analysis platforms. Customers will continue to receive updates as long as the relevant genetic markers were included in their DNA analysis.
This list is not comprehensive, and conditions not listed here are not necessarily included in our current health reports. Visit our complete list of health reports for a comprehensive list of conditions included in the 23andMe Service.
For more information about some of these conditions and where to inquire about testing, visit the resources below: