Purpose
Pseudoexfoliation (XFS) is a systemic disease and a frequent cause of glaucoma. The Lysyl oxidase-like 1 (LOXL1) gene is associated with XFS, but XFS-associated common variants in LOXL1 are present in >80% of individuals without XFS, suggesting involvement of additional genes and/or risk factors. The purpose of this study was to use the University of Utah Healthcare (UUHC) patient population and the Utah Population Database (UPDB) to identify families with of XFS to further investigate the genetic underpinnings and epidemiology of XFS.
Methods
To identify patients diagnosed with XFS, we analyzed UUHC records comprised of ~236,000 individuals and 1.1 million patient visits from 1996-2013 that link to Utah Population Data Base (UPDB) genealogies. We verified ICD-9 coded XFS cases by medical record review. We estimated the prevalence of XFS in the UUHC population, and identified families with excess risk of XFS using a familial standardized incidence ratio (FSIR) approach.
Results
We identified 1901 patients with ICD-9-coded XFS (365.52 and 366.11). Of 540 charts reviewed to date 90.7% were confirmed. The prevalence of XFS in the UUHC system was 0.8% based on age at diagnosis. Prevalence increased with age from 0.6% for 55-64 y, 2.2% for 65-74 y, and 3.0% for 75 y and older (Ptrend=0.0001). We identified 200 families with a significant excess of XFS (FSIRs P<0.0001 to P=0.008). The population attributable risk (PAR) for genetic effects was 10.0% (95%CI 1.0%-17.0%). Within these families, atrial fibrillation, HTN, and other cardiovascular diseases appear to co-segregate vs. UUHC patients in families with no XFS (OR=1.24, 95%CI 1.01-1.54; P=0.04).
Conclusions
The prevalence of XFS in the UUHC system was consistent with other studies in Caucasian populations. Using the UPDB, we identified the largest known set of high-risk XFS pedigrees. This set of 200 families supports a genetic inheritance of XFS (overall FSIR P=0.02), and association with several comorbidities. This large number of high-risk XFS families provides a resource for further investigation of the genetics and epidemiology of XFS.
Keywords: 463 clinical (human) or epidemiologic studies: prevalence/incidence •
464 clinical (human) or epidemiologic studies: risk factor assessment