Three independent studies used aCGH to examine the contribution of CNV to IPN and all concluded that apart from the CMT1A duplication/HNPP deletion, CNV as a disease mechanism in IPN is rare (Hoyer et al., 2015; Huang et al., 2010; Pehlivan et al., 2016). Here, PMP22 is linked to bile duct papillary neoplasm.