AbstractBackgroundHereditary ichthyosis constitutes a diverse group of cornification disorders. Identification of the molecular cause facilitates optimal patient care.ObjectiveWe wanted to estimate the diagnostic yield of applying whole‐exome sequencing (WES) in the routine genetic workup of inherited ichthyosis.MethodsDuring a 3‐year‐period, all ichthyosis patients, except X‐linked and mild vulgar ichthyosis, consecutively admitted to a university hospital clinic were offered WES with subsequent analysis of ichthyosis‐related genes as a first‐line genetic investigation. Clinical and molecular data have been collected retrospectively.ResultsGenetic variants causative for the ichthyosis were identified in 27 of 34 investigated patients (79.4%). In all, 31 causative mutations across 13 genes were disclosed, including 12 novel variants. TGM1 was the most frequently mutated gene, accounting for 43.7% of patients suffering from autosomal recessive congenital ichthyosis (ARCI).ConclusionWhole‐exome sequencing appears an effective tool in disclosing the molecular cause of patients with hereditary ichthyosis seen in clinical practice and should be considered a first‐tier genetic test in these patients.