Pelvic Pain Slideshow Birth Control Slideshow Pictures Take the Happiness Quiz! Agenesis: Lack of development. For example, agenesis of a toe means the toe failed to form. From Women's Health Resources Tips for Taking Your HIV Medicines5 Things That Spike Your Blood SugarComplementary Treatments for Cancer Featured Centers When Prostate Cancer SpreadsEssential Tips to Manage DiabetesWhat Is Cystic Fibrosis? What Causes It? Health Solutions From Our Sponsors Kept Your Wisdom Teeth? Therapy at Home?