<h4>Background</h4>CGG expansions in <i>NOTCH2NLC</i> and <i>LRP12</i> were recently identified as a cause of Charcot-Marie-Tooth disease (CMT) in 1.2%-10.6% of genetically undiagnosed patients in China, Taiwan and Japan. This evidence concerns the gene LRP12 and Charcot-Marie-Tooth disease.