KLK11-Related Disorder of Cornification Presenting as Inflammatory Skin Disease: A Familial Case Report and Literature Review.

Mendelian disorders of cornification (MeDoC) are a group of heterogeneous inherited skin disorders characterized by hyperkeratosis or scaling. Clinical assessment and skin biopsy are primarily used to differentiate MeDoC from overlapping diseases, including inflammatory skin diseases, and to identify the specific type of MeDoC; however, the results can sometimes be inconclusive. We present two individuals from a family who were initially misdiagnosed with familial pityriasis rubra pilaris, however clinical exome sequencing revealed a likely pathogenic variant in KLK11, a gene recently identified to be associated with MeDoC. This study emphasizes the importance of genetic testing in dermatologic diagnosis.