Your DNA
The genetics of glaucoma
Glaucoma is a common disease of aging that stems from both genetic and environmental causes. While it is mostly associated with non-inherited factors, 13 percent of the risk of developing glaucoma is hereditary, according to studies conducted on twins.
Other studies have demonstrated that certain genetic variants can lead to a greater chance of developing glaucoma. We test for a genetic marker associated with exfoliation glaucoma, a subtype of open-angle glaucoma, which is the most common type of glaucoma.
Knowing whether you have a genetic susceptibility to glaucoma can help you work with your doctor on early detection of this disease.
What we found for glaucoma
We looked at one place on your genome where a one-letter difference in the genetic code affects your odds of exfoliation glaucoma. At each location, there are two markers, for a total of two possible risk markers. You have zero of the two risk markers we looked for.
Glaucoma
- You:
- 0.47%
- Avg:
- 2.4%
Your genetic markers
|
Gene or location 
|
Risk marker
|
Your markers
|
Odds ratio
|
Source
|
|---|---|---|---|---|
|
LOXL1
|
T | C C | 1.0 | Science, 2007 |
What it means
Everyone has some chance of developing glaucoma. Each risk marker increases your odds by a different amount — some a little, some a lot. The "odds ratio" column in the chart above shows their relative impact.
About genetic markers
More than 99 percent of our genetic code is identical from person to person. The remainder is unique among individuals and gives rise to our diversity. DNA, the chemical instructions that determine our genetic code, is inherited from our parents and is composed of four biochemical bases that are represented by the DNA alphabet: A, T, G and C.
SNPs, or single nucleotide polymorphisms, are one-letter variations in our DNA. Each SNP (pronounced "snip") consists of two markers or variants, one inherited from each of our parents, and each marker has two possible versions, a risk version and a non-risk version. For example, at a given SNP, the base A may be the risk marker and the base G may be the non-risk marker. At another SNP, G may be the risk marker and T the non-risk marker.
The SNPs included in your Navigenics risk estimate have been reliably shown to be associated with diseases, although it is not known exactly how they contribute to the conditions. The degree of genetic risk you inherit is related, in part, to how many risk markers you have residing at each SNP — none, one (from one parent) or two (one from each parent). Just because you may have one or even two risk markers does not mean that you will definitely develop a given health condition, but it can raise your risk, especially if other lifestyle or environmental risk factors are present.