Should the test prove clinically viable, it could lead to new biomarkers for eye disease diagnostics and a new assay for clinical laboratories
Scientists at Flinders University in Australia have developed a genetic blood or saliva test that, they say, is 15 times more effective at identifying individuals at high risk of glaucoma than current medical laboratory tests.
If so, this discovery could lead to new biomarkers for diagnostic blood tests that help medical professionals identify and treat various diseases of the eye. Their test also can be performed on saliva samples. The researchers plan to launch a company later in 2022 to generate an accredited test that can be used in clinical trials.
“Early diagnosis of glaucoma can lead to vision-saving treatment, and genetic information can potentially give us an edge in making early diagnoses, and better treatment decisions,” said lead researcher Owen Siggs, PhD, Associate Professor, College of Medicine and Public Health at Flinders University, in a university press release.
Flinders University researchers have been collaborating with scientists at the QIMR Berghofer Medical Research Institute and other research institutes worldwide for some time to identify genetic risk factors for glaucoma, the press release noted.
“In the cross-sectional study of monogenic and polygenic variants related to the disease, the new genetic test was evaluated in 2,507 glaucoma patients in Australia and 411,337 people with or without glaucoma in the UK. The test, conducted using a blood or saliva sample, could potentially detect individuals at increased risk before irreversible vision loss happens,” Medical Device Network reported.
Who Is at Risk for Glaucoma?
Glaucoma is a group of eye diseases that are typically caused by a buildup of pressure within the eye. The eyeball contains and produces a fluid called aqueous humour which provides nutrition to the eye and keeps the eye in a proper pressurized state. Any excess of this fluid should be automatically released via a drainage canal called the trabecular meshwork.
But that’s not always the case. When the fluid cannot drain properly, intraocular pressure is created. Most forms of glaucoma are characterized by this pressure, which can damage the optic nerve and eventually cause vision loss and even blindness. Treatments for the disease include medications, laser treatments, and surgery.
Anyone can develop glaucoma, but according to the Mayo Clinic, individuals at higher risk of the disease include:
Individuals over the age of 60.
Those with a family history of glaucoma.
People of African, Asian, or Hispanic descent.
Patients with certain medical conditions, such as diabetes, heart disease, high blood pressure, and sickle cell anemia.
Those with corneas that are thin in the center.
Individuals who have had a past eye injury or certain types of eye surgery.
People who have taken corticosteroid medications, especially eyedrops, for an extended period of time.
Glaucoma is the second leading cause of blindness worldwide, particularly among the elderly. When diagnosed early, the condition is manageable, but even with treatment, about 15% of glaucoma patients become blind in at least one eye within 20 years.
According to the federal Centers for Disease Control and Prevention (CDC), approximately three million Americans are living with glaucoma. The disease often has no early symptoms, which is why it is estimated that about 50% of individuals who have glaucoma do not realize they have the illness.
Thus, a clinically-viable genetic test that is 15 times more likely to identify people at risk for developing glaucoma in its early stages would be a boon for ophthalmology practices worldwide and could save thousands from going blind.
More research and clinical trials are needed before the Flinders University genetic test for glaucoma becomes available. But the discovery alone demonstrates the importance of continuing research into identifying novel biomarkers that could be incorporated into useful clinical laboratory diagnostic tests.
In the same way that BRCA1 and BRCA2 mutations helped pathologists identify women with increased breast cancer risks in the late 1990s, this new study isolates an additional 72 mutations medical laboratories may soon use to diagnose breast cancer and assess risk factors
For 20 years genetic scientists, anatomic pathologists, and medical laboratories have employed the BRCA1/BRCA2 genes to identify women at higher risk for breast cancer. And, because pathologists receive a high number of breast biopsies to diagnose, physicians and clinical laboratories already have collaborative experience working with genetic mutations supported by ample published evidence outlining their relationship with cancer.
Now, a global research study is adding 72 more mutations to the list of mutations already known to be associated with breast cancer.
In coming years, physicians and anatomic pathologists can expect to use the knowledge of these 72 genetic mutations when diagnosing breast cancer and possibly other types of cancers in which these mutations may be involved.
New Precision Medicine Tools to Improve Breast Cancer Survival
Combining the efforts of more than 550 researchers across 300 institutions and six continents, the OncoArray Consortium analyzed the DNA of nearly 300,000 blood samples. The analysis included samples of both estrogen receptor (ER-positive and ER-negative) cases.
Taken from a study published in the British Journal of Cancer, the graph above illustrates “proportions of familial risk of breast cancer explained by hereditary variants.” It is expected that anatomic pathologists will eventually incorporate these genetic variants into diagnostic test for breast and other cancers. (Graphic copyright: British Journal of Cancer.)
The results of their research were published in two separate studies: one in the scientific journal Nature and the other in Nature Genetics. The studies outlined 72 newly isolated genetic mutations that might help quantify the risk of a woman developing breast cancer in her lifetime.
Among the 72 mutations, seven genes were specifically associated with ER-negative cases. ER-negative breast cancer often fails to respond to hormone therapy. Thus, this discovery could be crucial to developing and administering precision medicine therapies tailored to specific patients’ physiologies and conditions. Treatments that improve patient outcomes and overall survival rates in ER-negative and ER-positive breast cancers.
Genetics Could Help Clinical Laboratories Wage War on All Cancers
According to data published by the Centers for Disease Control and Prevention (CDC), breast cancer is the most common form of cancer among women of all races. It’s the second-leading cause of all cancer deaths among most races and first among Hispanic women.
In the past, it was estimated that 5-10% of breast cancers were inherited through the passing of abnormal genes. However, Lisa Schlager, Vice President of community affairs and public policy for FORCE (Facing Our Risk of Cancer Empowered), told CNN, “This new information may mean that that estimate is low.” FORCE is a national nonprofit organization dedicated to fighting hereditary breast, ovarian, and related cancers.
Schlager calls upon health systems to “embrace the ability to use genetic information to tailor healthcare by providing affordable access to the needed screening and preventive interventions.” As precision therapy and genetic analysis continue to shape the way patients are treated, medical laboratories will play a significant role in providing the information powering these innovative approaches.
Kraft notes that samples were sourced from women of primarily European ancestry. Further study of other ethnic populations could lead to yet more mutations and indicators for cancers more common outside of the European region.
Research authors also highlight the importance of continued standard screening, such as mammograms. However, they suggest that genetic mutations, such as those found in the OncoArray study, might be used to highlight high-risk individuals and screen sooner, or conduct more in-depth genetic analyses, to catch potential cancer cases earlier and improve outcomes.
“Many women are offered mammogram screening when they are middle-aged,” Georgia Chenevix-Trench, PhD, co-author of the Nature Genetics study and researcher at the QIMR Berghofer Medical Research Institute in Australia, told LabRoots. “But if we know a woman has genetic markers that place her at higher risk of breast cancer, we can recommend more intensive screening at a younger age.”
Anatomic pathologists and clinical laboratories can use these new insights to offer increased options for oncologists and physicians on the front lines of the battle against cancer. While the list of genetic mutations related to cancer is far from complete, each added mutation holds the potential to power a new treatment, improve early detection rates, and improve survival rates of this global killer.