Purpose: Myopia (short sightedness) is a complex trait influenced by as yet unidentified genetic factors. To date, there have been four myopia susceptibility loci (MYP7 to -10) identified in twin studies, but these are yet to be independently verified. In an independent yet ethnically and phenotypically similar twin cohort, linkage to these chromosomal regions was sought.
Methods: Participants were 223 dizygotic twin pairs from the Australian Twin Registry who were assessed for evidence of linkage, by using polymorphic microsatellite markers spanning MYP7-10. Data were analyzed by using Haseman-Elston regression analysis.
Results: No evidence of linkage of myopia or its underlying biological components such as eye length to the MYP7-10 regions was found in this twin cohort.
Conclusions: This is the first study to assess for linkage in a secondary myopia twin cohort and highlights the problems associated with applying linkage results from complex traits to the other populations.