The Complex Disease Model of Glaucoma

S ince Pratap Challa, MD, wrote about genetics and glaucoma for Glaucoma Today in 2003,1 investigators have expanded previously successful research to identify more genes associated with this potentially blinding disease. This article updates the ongoing search for genetic markers for glaucoma and genes that contribute to the disease’s onset and progression, discusses the shift from a singlegene to a complex disease model, and suggests how genomic testing may help clinicians develop personalized treatments for their patients in the future. IDENTIFYING GENETIC MARKERS Traditionally, researchers have collaborated with patients, members of patients’ families, clinicians, and geneticists to identify genetic markers for diseases. This approach has led to the identification of 70 genes, chromosomal regions containing genes (ie, loci), and alleles that either cause glaucoma or are associated with syndromes encompassing glaucoma (Table 1). The highly penetrant forms of glaucoma associated with these genes include infantile-onset, juvenile-onset, and syndromic glaucoma as well as a very Glaucoma and Genomic Medicine