Structural disorders such as flat feet, hyperextended knees (genu recurvatum), and hypermobility syndrome (joints that can move beyond the normal range of motion) may predispose a person to developing leg cramps.
It's important to avoid excessive sun exposure when taking St. John's Wort as it may predispose you to photosensitivity, or light sensitivity, and cause your skin to burn more so than usual.
All MEN types are the result of inherited genetic mutations that predispose the individual to excessive growth of cells (hyperplasia) and tumor formation in multiple endocrine glands.
There may also be biologic factors such as attention-deficit/hyperactivity disorder (ADHD) and certain temperaments that predispose particular children towards misbehavior.
Although it is uncertain why the hair follicles undergo these changes, it is thought that a combination of genes may predispose some children and adults to the disease.