Netherton syndrome previously misdiagnosed as hyper IgE syndrome caused by a probable mutation in SPINK5 C

Netherton syndrome (NS, MIM256500) is an autosomal recessive disorder that includes ichthyosis linearis circumflexa and a predisposition to allergies, asthma, and eczema, with hypereosinophilia, trichorrhexis invaginata, and elevated serum IgE levels. The genetic bases of Netherton syndrome are mutations in the gene SPINK5, and the Lymphoepitheial Kazal type related inhibitor, a serine protease inhibitor, is encoded by SPINK. Here a case is presented which showed a probable splice site mutation in SPINK5, which was previously unknown in databases and the literature, to point out the misdiagnosis of Hyper IgE Syndrome in the early presentation of the phenotype. This case highlights that a genetic test can be critical for identifying NS. The finding of underlying mutations contributes to the understanding of Netherton syndrome and is instrumental in indicating a specific therapy. Notably, treatment with acitretin has significantly improved both the ichthyosis linearis circumflexa and eczema in our patient.