Opthalmic examination of Dizygotic twins in Queensland
Glaucoma is thought to have a major genetic component. Several genes have been identified, but so far these only accounts for 5% of glaucoma cases. Twin studies are an important tool for determining the relative contribution of genes or environment in any measure. If there is very little genetic component, then identical twins will vary as much as non identical twins. Dr. Mackey will analyze pressure, refraction, optic nerve, corneal thickness and many other measures in his study, and then compare all the numerical measurements of the twins with their DNA markers to discover where similar twins consistently have similar DNA markers. Discovering the genes that cause glaucoma will enable other family members to be tested and predict who is at high risk or low risk of developing glaucoma. This will allow better early screening for glaucoma and potentially lead to the development of new treatments.
Zhu, G., Hewitt, A.W., Ruddle, J.B., Kearns, L.S., Brown, S.A., MacKinnon, J.R., Chen, C.Y., Hammond, C.J., Craig, J.E., Montgomery, G.W., Martin, N.G., and Mackey, D.A. (2007) Genetic dissection of myopia: evidence for linkage of ocular axial length to chromosome 5q. Ophthalmology. 2007 Oct 25.
Burdon KP, Macgregor S, Hewitt AW, Sharma S, Chidlow G, Mills RA, Danoy P, Casson R, Viswanathan AC, Liu JZ, Landers J, Henders AK, Wood J, Souzeau E, Crawford A, Leo P, Wang JJ, Rochtchina E, Nyholt DR, Martin NG, Montgomery GW, Mitchell P, Brown MA, Mackey DA, Craig JE. Genome-wide association study identifies susceptibility loci for open angle glaucoma at TMCO1 and CDKN2B-AS1. Nat Genet. 2011 Jun;43(6):574-8.
First published on: June 10, 2008
Last modified on: June 18, 2011