CDSN and hypohidrosis: It may be due to the fact that the family pedigree in this case is characterized by a single mutation in CDSN, whereas all known PSD-causing CDSN mutations are either homozygous or compound heterozygous (Oji et al., 2010; Israeli et al., 2011; Mazereeuw-Hautier et al., 2011; Telem et al., 2012; Mallet et al., 2013; Kawakami et al., 2014), and the mode of inheritance is autosomal recessive, which rationally explains the patient’s manifestation of hypohidrosis without observing any abnormal skin manifestations.