Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.PURPOSE: To describe a novel mRNA mutation associated with ligneous conjunctivitis (LC) in a patient with heterozygous familial Mediterranean fever (FMF) mutation. METHODS: Case presentation of a patient with LC and heterozygous FMF mutation. The patient was evaluated for various genetically predisposed inflammatory diseases through whole exome sequencing. RESULTS: LC is a rare inflammatory ocular pathology presenting with recurrent conjunctivitis episodes with eosinophilic fibrin-rich pseudomembranes. FMF is an autoinflammatory disease presenting with recurrent episodes of fever, arthritis, and other inflammatory conditions. Various plasminogen (PLG) gene mutations have been identified in LC, whereas a variety of mutations in the Mediterranean fever (MEFV) gene have been identified in FMF patients. Based on the inflammatory nature of both pathologies, we aimed to evaluate and identify any potential common genetic pathway. We were not able to identify any mutation in PLG gene through whole gene sequencing; however, the patient was positive for heterozygous M680I FMF mutation, and we observed 22% of NM_000301.3:c.2130T>G (p.T710=) variant in mRNA isolated from affected tissue, which was not present in DNA sequence. CONCLUSIONS: To the best of our knowledge, this is the first case of LC caused by an mRNA mutation coexisting with another genetically predisposed autoinflammatory disease mutation.