Karen Usdin, PhD, is the deputy chief of the Laboratory of Cell & Molecular Biology and the section chief of the Gene Structure and Disease Section  Laboratory of Cell & Molecular Biology within the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at the National Institutes of Health (NIH). Dr. Usdin’s work focuses on repeat expansion diseases, including FMR1-related disorders (a.k.a. Fragile X–related disorders), Friedreich ataxia, and Glutaminase deficiency disorder. The Usdin lab is interested in the mechanism responsible for the unusual mutation that causes these diseases as well as the consequences of these mutations.