Abstract
Purpose :
There has been struggle in identifying genetic risk factors for Keratoconus due to its complex etiology and inheritance patterns. Among common approaches used to pin-point genetic components in families with autosomal dominant presentation of this entity, the analysis of candidate genes has been employed to study affected cohorts. We assessed the genetic variant rs121908120 in the WNT10A gene, with the objective of recognizing patients with risk of developing Keratoconus and identifying those at risk of presenting the disease at an early age in a Mexican population sample.
Methods :
87 Mexican patients with strict Keratoconus criteria and the same number of healthy control patients where included. A 4ml blood sample of each of the included subjects was required for DNA extraction using the automated protocol for the QIAcube using the “QIAamp DNA Mini” kit. We then proceeded to analize the extracted DNA using rtPCR techniques (allelic discrimination) with specific Taqman probes for the rs121908120 variant and Thermo Science reagents for the reactions.
Results :
Statistical analysis was made using the "Prysm" software, where a chi square test was performed for categorical variables and to confirm the existence of a Hardy-Weinberg equilibrium in the control group. Odds ratio was calculated with confidence intervals of 95% and Alpha level of 0.05, considering values greater than 1 as risk for Keratoconus. The variant rs121908120 of this gene showed a P value of 1 and an Alpha level <0.05, indicating it is not a risk factor for our studied cohort. From the total of case samples, 7 where heterozygote for the rs121908120 variant and 80 were wild type or normal. In the control group, 14 samples were heterozygote and 73 were wild type. More control samples were positive for the variant than in the case group, indicating that the analysis would not be statistically significant.
Conclusions :
Based on cohort studies worldwide, it is clear that the WNT10A gene has an important role in corneal stability. We concluded that the rs121908120 variant of the WNT10A gene is not a risk factor for the development of Keratoconus in our Mexican population sample. The association of the WNT genes and their expression in different ocular tissues, suggest a larger population sample and a better variant mapping could be useful in genetic association studies worldwide.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.