At one time or the other, virtually every parent has gone to the doctor concerned about his or her child. Thanks to the advances of modern medicine, the doctor can diagnose the problem most of the time and treat it successfully. Many potential problems, some life-threatening like diphtheria and neural tube defects, can even be prevented altogether with procedures like vaccinations and effective prenatal and perinatal care. However, there are going to be times when answers aren't available. These are the occasions when all concerned become painfully aware of the need for more knowledge--about the body, about development, and often, in the case of developmental disabilities, about the brain. Modern technological developments are providing incredibly powerful methods for gaining new insights into the miraculous processes that make each one a unique individual. This article discusses one of these developments, which involves the use of microarrays in the study of genetics.