PMP22 and Charcot-Marie-Tooth disease type 1A: Although no studies have reported milder symptoms in de novo CMT1A patients compared to non‐de novo patients, several reports have suggested genetic anticipation showing more severe clinical symptoms and younger age of onset over generations in CMT1A patients (Dupré et al., 1999; Kovach et al., 2002; Steiner et al., 2008).