Nonsense Variant in CYP4F22 Causes Malformation of Corneocyte Lipid Envelopes in a Lamellar Ichthyosis Patient

Cytochrome P450 4F22 (CYP4F22), encoded by CYP4F22, is a protein proposed to be integral to the healthy formation of the corneocyte lipid envelope (CLE) (1).CYP4F22 deficiency clinically results in lamellar ichthyosis (LI), a type of autosomal recessive congenital ichthyosis (ARCI) (1).A number of variants in CYP4F22 have been identified as being pathogenic for LI, with the majority of reports originating from families with Mediterranean or Middle-Eastern backgrounds (2).Here, we report a patient with LI carrying a novel CYP4F22 variant.In-depth analysis successfully demonstrated the loss of CLE in the stratum corneum, which has not been reported previously. CASE PRESENTATIONThe patient, a 14-year-old girl originally from Afghanistan, presented with erythematous, dry, scaly skin since birth.On examination, there was scaling over almost the entire body, with mild pain and itching (Fig. 1A,B).She was born to consanguineous parents (cousins).Two of her 9 uncles were reported to have similar symptoms.Neither she nor her affected uncles had received any treatment previously.She was started on treatment with emollients and topical steroids.The treatment improved her erythema and scaling to some extent, although she never achieved full remission.She has remained on regular follow-up at our hospital since.