Although this specific large duplication has not previously been documented, duplications of chromosome 17p11.2 region which contain the PMP22 gene causes Charcot-Marie-Tooth type 1A (CMT1A) and have been shown to lead to increased gene dosage as the functional defect in patients with CMT1A.9 Based on these considerations, this variant was classified as pathogenic. The gene discussed is PMP22; the disease is Charcot-Marie-Tooth disease type 1A.