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Why Genetic Testing Is the Key to Earlier Rare Disease Diagnoses

genetic testing-diagnosis-rare disease diagnosis-genetic test-primary immunodeficiency
genetic testing-diagnosis-rare disease diagnosis-genetic test-primary immunodeficiency

There are more than 450 types of primary immunodeficiency (PI), a rare, chronic, genetic disorder that affects approximately 500,000 Americans.


People with PI are prone to a wide range of infections and are at increased risk of certain cancers and autoimmune disorders. It is a life-threatening and lifelong condition. 

Because PI often presents in the form of infections, clinicians treat the infection while missing the underlying cause. Thousands go undiagnosed, and even for those with a diagnosis, it can take 9-14 years from the onset of symptoms to get a proper diagnosis and treatment.  

Because this group of diseases is caused by defects in genes involved in the development and functioning of the immune system, genetic testing is often required to ensure an accurate diagnosis. Genetic testing may also hold the key to early diagnosis, proper treatment, and an increased understanding of the prevalence of PI. 

Lasting benefits 

There are many benefits to a genetic test, even after an initial diagnosis.  Among them is the ability to make more informed healthcare choices; knowledge about risk to family members, which could inform family planning decisions; an understanding of options for taking part in clinical research; and knowledge as you look for resources (like patient communities and organizations) specific to your own condition.  


According to a recent study in Immunologic Research, 45 percent of patients received an updated clinical diagnosis and 36% had their treatment protocols changed by their physician after genetic testing. These results demonstrate the cost-efficiency, utility, and importance of genetic testing for patients with PI when working with their medical provider.  

Four questions for genetic testing

There are four key questions that you should ask your doctor when considering genetic testing:  

  1. You will want to ask if you’ve ever had a genetic test, and if you have, you’ll want to ask if you should consider retesting since genetic tests have expanded and now include more than 400 genes. There are free genetic tests available with a doctor’s referral.   
  1. You should ask if you qualify for one.   
  1. You should ask your physician if the results of a genetic test will alter your treatment management program.  
  1. You will want to ask your physician if they recommend you as a candidate for genetic testing.  

For people who qualify, there may be a no-charge genetic testing program available. There are currently two sponsored, no-charge genetic testing programs available that include pre- and/or post-testing genetic counseling services. If you are a resident of the United States or Canada, talk to your doctor to determine if you meet the criteria to qualify for either genetic testing program. 

You can learn more at

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