Genetic testing and new variants in diagnosis of congenital ichthyoses

Abstract Background The aim of this study was to evaluate how diagnostic practice in congenital ichthyoses has evolved during the years 2000–2020 and what kind of gene variants of congenital ichthyosis have been found. Methods The study cohort of this register‐based research consisted of a total of 88 patients, whose diagnostic testing was conducted, and ichthyosis diagnoses set at the Department of Dermatology and the Department of Clinical Genetics at Tampere University Hospital during the years 2000–2020. Results Diagnosis of ichthyosis was confirmed with genetic testing in 33 cases, and with conventional diagnostic methods, such as clinical findings, skin biopsy and family history of ichthyoses, in 55 cases. We observed four novel variants in patients with the clinical diagnoses of congenital ichthyoses. Conclusion When genetic testing became available, it was offered primarily to patients with severe forms of ichthyosis. During the study period next‐generation sequencing became the genetic testing method of choice providing new opportunities in diagnostics.