A new American study has successfully located three new genetic loci linked with the disease Fuchs endothelial corneal dystrophy (FECD). With this new data, doctors can hopefully identify a person's genetic predisposition to FECD far earlier in life.
This international study was officially the largest ever conducted looking specifically at the genetics of FECD. 5,417 people in total participated in this study, 2,075 of which had FECD.
Geneticists at 16 different locations around the world collaborated on this study. As they compared data from people with and without FECD, they found that three new genetic loci were linked with the disorder. These three genes include LAMC1, ATP1B1, and KANK4.
Previous studies looking into this issue only discovered a link between FECD and the gene TCF4. When researchers on this international study looked at TCF4, they did confirm that it is linked to FECD just like LAMC1, ATP1B1, and KANK4.
One major finding from this latest FECD study was that variants in certain genes will affect men and women differently. Researchers found that variants in LAMC1 put women at a greater risk of developing FECD, but variants in TCF4 conferred greater risk to men.
With all of this information, researchers believe they can better predict a person's susceptibility to FECD. Specifically, scientists believe they can tell a person's susceptibility to the eye disease with 78 percent accuracy just by using these four genetic loci.
As of today, the only way to screen for FECD is by using family history. The study's authors hope their research will help develop clinical screening tools and molecular diagnostic tests to look for FECD susceptibility.
Professors involved in this study studied the eyes of living and dead patients using numerous methods. A few techniques used in this international study include immunohistochemistry and investigating discarded corneal tissue.
FECD is considered a progressive disease that destroys a patient's cornea. The disease starts when corneal endothelial cells die off in a central area of the cornea called the endothelium. While most people lose endothelial cells as they grow older, people with FECD lose them at a faster rate and earlier in life.
When the endothelium fails, the eye becomes filled with liquid and starts to swell. This swelling process is called "edema."
The corneal edema is the first sign of FECD. Patients often experience extremely cloudy vision at the start of the day that clears up after the cornea dries out. If left unchecked, FECD could lead to painful blisters and an inability to focus.
At the early stages of the disease, people can fix their hazy morning vision by using a hairdryer to dry out their eyes. Of course, as the disease gets worse, this strategy won't work so well. That's why FECD is still the number one cause of corneal transplantation in the world.
FECD currently affects 4 percent of people aged 40 and above across the globe.
This revolutionary study was published in the magazine Nature Communications under the title "Genome-wide association study identifies three novel loci in Fuchs endothelial corneal dystrophy." Major funding for this research came from the National Eye Institute.