PNPLA1 and ichthyosis: To investigate the genetic defects for patients with ichthyosis, a panel of 25 genes (ABCA12, ALOX12B, ALOXE3, CLDN1, COL17A1, COL7A1, CYP4F22, FLG, ITGA6, ITGB4, KRT14, KRT5, LAMA3, LAMB3, LAMC2, MBTPS2, NIPAL4, PLEC, PNPLA1, SLC27A4, SNAP29, SPINK5, ST14, STS, and TGM1) underlying the most common genetic defects for ichthyosis was detected by NGS (BGI-Wuhan).