Courtagen Life Sciences Blog

How Courtagen's Genetic Tests Differ from 23andMe

Posted by Cheryl Scacheri, MS, LGC on Oct 26, 2016 3:46:02 PM

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Patients and providers often ask “What’s the difference between Courtagen’s tests and 23andMe?”

The genetic tests done by Courtagen and 23andMe are similar in that both companies extract human DNA from saliva samples and look for differences in the genetic code. 23andMe, as well as other direct to consumer genetic testing companies, only provide SNP testing, which is useful for getting information about common DNA variations. Courtagen offers SNP testing as well, but our main offering is targeted DNA sequencing panels that can identify rare DNA variations. The expert interpretation included in Courtagen reports and availability of our genetic counselors to help explain results, make Courtagen tests a powerful diagnostic tool that healthcare professionals can use to diagnose and treat genetic diseases.

Here are some of the ways Courtagen's genetic tests differ from 23andMe’s testing.

 

Courtagen test results can be used to diagnose genetic diseases

DNA variations occur frequently. Most are common, non-disease causing variants called single nucleotide polymorphisms (SNPs). SNPs (pronounced “snips”) determine a person’s physical characteristics, such as hair color, eye color, height, and skin color as well as their overall health and risk for certain diseases. When combined with environmental or lifestyle factors, some SNP variations may lead to disease; however, SNP variations alone do not cause disease, so SNP testing is only one piece of the genetics puzzle. However, it is important to note that results from testing SNPs do not provide a definitive or actionable diagnosis for genetic disease.

Courtagen’s diagnostic tests look beyond SNPs and common DNA differences to identify rare variants in the patient’s DNA. Rare variants can negatively affect the way a gene functions, which can significantly impact the patient’s health and cause disease. The presence of certain rare variants in a patient’s DNA can be used to make a definitive or actionable diagnosis for genetic disease.

Diagnosing rare genetic disorders enables appropriate medical management and sometimes treatments, and provides valuable information to family members about how and if a disorder is inherited.

 

Courtagen tests sequence entire genes

Courtagen’s expertise is in a state-of-the-art method called Next Generation Sequencing (NGS). Instead of “spot checking” common variant locations scattered throughout a person’s DNA, Courtagen’s diagnostic analysis looks at all genes that are known to be associated with a person’s symptoms. Using NGS, Courtagen can identify rare variants within genes that cannot be identified with SNP testing.

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For example, the MTHFR gene provides instructions for making an enzyme that processes amino acids, the building blocks of proteins. There is a well-known SNP within the MTHFR gene (C677T) that may indicate a risk factor for cardiovascular disease, thrombosis, recurrent pregnancy loss, birth defects and neurodevelopmental and neuropsychiatric disorders. This SNP variant is present in about 30% of the population. It is important to note, however, that risk factors may increase the probability for contracting a certain disease, but are not the direct cause of the disease. However, there are rare, disease-causing variants in the MTHFR gene that cause homocystinuria, a treatable childhood-onset disorder. For example MTHFR L323P is a rare variant that causes homocystinuria, which is only found in 0.0025% of the population. MTHFR L323P  can be identified through the NGS testing done by Courtagen. It can’t be identified with a SNP test.

The difference between 23andMe’s SNP testing and Courtagen’s full gene NGS testing is like comparing the process of grading a multiple choice test and proof reading a book.

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Courtagen provides expert interpretation and support

Not all variants are harmful, so interpreting the meaning of a rare variant is essential. Courtagen uses a computer program that scores the variants to determine whether they are disease causing. Courtagen’s bioinformatics algorithms use dozens of pieces of evidence, including scientific literature, scientific experiments, previous observations in the population, family testing, and computational information to determine a variant’s significance. Interpretation provided in Courtagen’s diagnostic test results can be used to make a definitive diagnosis, inform treatment decisions, avoid potential triggers, determine inheritance patterns, and help families get access to clinically appropriate support services.

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Courtagen’s genetic counselors are available to speak with health care professionals about the diagnostic testing results, assist with explaining the interpretation of the results, and answer any other questions that may arise.

If you have any questions about genetic testing, don’t hesitate to contact us. 

Topics: Genetic Testing, Genetics