Is Pseudoexfoliation Syndrome Inherited? Results from the Reykjavik Eye Study (RES)

Abstract

Abstract: : Purpose: To identify families with two or more affected individuals in 6 meiosis and to examine the relatedness of persons with definite pseudoexfoliation (PEX) in the RES as compared to comparable random samples from the population. Methods: The RES included a random sample from the population census of 1045 persons who were ≥50 years old and participated in the RES in 1996. After dilation of the pupil a slit lamp examination was performed looking specifically for PEX. Participants with partial or complete central shield with or without a peripheral band in at least one eye were considered to have PEX. We constructed family trees in 6 meiosis (2^nd cousins) where two or more family members were found to be affected using the genealogical database of deCode Genetics. We then used the genealogical database to compare the relatedness of those with definite PEX with control groups created from a random sample from the Icelandic population. Results: 108 persons were identified as having definite PEX. In 6 meiosis, 6 family trees were found to have two affected persons and two family trees to have three affected persons, altogether 8 males and 10 females. We created 1000 random sample controls from book of Icelanders with same age, sex and connectivity stratification as those affected. This was done with depth of 5 generations (10 meiosis). Thus the program begins finding all the ancestors of the persons in the file to the maximum depth marked by the depth decided.We used localfind sharing (software) to check with Monte Carlo simulation if the affecteds are more related than the controls. This was simulated 5000 times for each sample and resulted in p=0.387 i.e. the affecteds were not statistically significantly more related than the random sample from the Icelandic population. We also calculated the kinship-coefficient = 1.441242644513648E-4 indicating that the affecteds are not more related than the random controls. Conclusions: Comparing those affected with PEX in the RES with random samples from the population, the affecteds are not found to be significantly more related than controls.

Keywords: genetics • anterior segment • aging