Lipodystrophy disorders are characterized by selective loss of fat tissue with metabolic complications including insulin resistance, hypertriglyceridemia, and nonalcoholic liver disease. These complications can be life-threatening, affect quality of life, and result in increased health care costs. Genetic discoveries have been particularly helpful in understanding the pathophysiology of these diseases, and have shown that mutations affect pathways involved in adipocyte differentiation and survival, lipid droplet formation, and lipid synthesis. In addition, genetic testing can identify patients whose phenotypes are not clearly apparent, but who may still be affected by severe metabolic complications.