The job of the medical geneticist is to recognize genetic disorders and birth defects, to understand the significance of these with respect to the well-being of the patient, to arrange for proper treatment, and perhaps most important, to help the patient and/or the patient's family understand and cope with the disorder. This specialist uses modern cytogenetic, radiologic, and biochemical testing to assist in specialized genetic counseling, implements needed therapeutic interventions, and provides prevention through prenatal diagnosis. A medical geneticist plans and coordinates large scale screening programs for inborn errors of metabolism, hemoglobinopathies, chromosome abnormalities, and neural tube defects. Some medical geneticists work primarily with infants and children. Other medical geneticists, often those who are first trained as obstetricians, concentrate on the genetic problems of fetuses. Internists with training in medical genetics work with adult patients who may have familial forms of heart disease, cancer, or neurological disease. There are also opthalmologists, dermatologists, and pathologists who are medical geneticists.Great strides are being made in many areas of human genetics, leading to deeper understanding of the basic functions of genes. Such technologic advances also give rise to new methods of diagnosis and treatment. An increasingly important role of the medical geneticist is to act as the link between scientists who are making these technologic advances and patients who may benefit from them.