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Benefits of Exome Testing

Exome testing has higher diagnostic yields

Numerous studies have demonstrated the clinical utility of exome testing for diagnosis. Due to its broad approach in interrogating the genome, exome testing often has a higher diagnostic rate compared to traditional genetic testing, although this depends on the specific clinical presentation. Diagnostic rates of 20-58% have been reported for patients tested by a genetic provider.

Examples of indications with demonstrated diagnosis rates include:

  • critically ill children (diagnostic rates as high as 75%)
  • hearing loss (55%)
  • vision impairment (47%)
  • neurological disease, neurodevelopmental/intellectual delay (20-43%)
  • neurodevelopmental delay (45%)
  • musculoskeletal system (40%)

Exome testing may shorten time to diagnosis for some patients

Coming to a diagnosis can be especially important to patients who have been unable to obtain an answer to explain their condition, known as a "diagnostic odyssey," regardless of whether the diagnosis confers new treatment or management options. Exome testing not only has the possibility of reaching a diagnosis sooner but has been shown to be cost-effective for some patients. Exome testing may also identify more than one genetic condition in an individual, explaining an atypical patient presentation.

Utility of exome testing is increasing across the lifespan

Prenatal. Although exome testing is not yet commonly used in the prenatal period, it has shown detection rates of over 40% for fetuses with ultrasound abnormalities and appears in published clinical guidelines from the American College of Medical Genetics and Genomics as an appropriate test to be considered for select fetuses with a likely genetic disorder. Detection rates are higher with fetuses with more structural anomalies.

Pediatric. Exome testing is increasingly being used for children when a genetic etiology is suspected. The use of rapid genomic testing for babies in the NICU provides the opportunity for rapid diagnosis, decreased mortality, and facilitation of decisions about treatment and palliative care. While typical exome or whole genome sequencing can take weeks to months, rapid testing can have results in as few as 24 hours in the NICU setting.

Adult. Exome testing has clear utility in adults, albeit with a lower yield than in children (although this depends greatly on the patient’s presentation).

Personal utility

In addition to the benefits discussed above, patients can find personal utility in exome testing. Patients may perceive exome testing to be valuable for both medical and non-medical reasons, including getting answers about etiology of disease, identification of treatment options, prognosis, familial risk, and family planning. Non-medical value can include enhanced coping, preparation, self-knowledge, advancement of science, and empowerment. Much of the literature advocates for taking personal utility into consideration during the decision-making process.