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Aims Ornithine transcarbamylase (OTC) is an enzyme of the urea cycle catalyzing the condensation of carbamyl phosphate and ornithine to form citrulline. OTC deficiency leads to elevated serum ammonia and presents as different neurological or psychiatric symptoms. OTC deficiency is an X-linked inborn error of metabolism and most cases occur in neonatal period with severe presentation. Lesser known is the late-onset form that remains latent from infancy and only presents with intriguing symptoms mimicking psychiatric disease in adulthood. Methods Case report. Results We describe a case of adult-onset OTC deficiency in a 40-year-old man with borderline intellectual functioning and a psychotic episode following a protein rich meal. The case was first diagnosed as undifferentiated schizophrenia, until the genetic study was carried out. Conclusion Awareness of the adult onset ornithine transcarbamylase deficiency being a rare but possible differential diagnosis in a patient with acute psychiatric symptoms with hyperammonemia. Organic causes such as cerebral, metabolic, toxic causes of psychosis should be actively sought especially when encountering cases of acute psychosis.

Pattern recognition receptors (PRRs) are crucial for responses to infections and tissue damage; however, their role in autoimmunity is less clear. Herein we demonstrate that 2 C-type lectin receptors (CLRs) Mcl and Mincle play an important role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Congenic rats expressing lower levels of Mcl and Mincle on myeloid cells exhibited a drastic reduction in EAE incidence. In vivo silencing of Mcl and Mincle or blockade of their endogenous ligand SAP130 revealed that these receptors' expression in the central nervous system is crucial for T cell recruitment and reactivation into a pathogenic Th17/GM-CSF phenotype. Consistent with this, we uncovered MCL- and MINCLE-expressing cells in brain lesions of MS patients and we further found an upregulation of the MCL/MINCLE signaling pathway and an increased response following MCL/MINCLE stimulation in peripheral blood mononuclear cells from MS patients. Together, these data support a role for CLRs in autoimmunity and implicate the MCL/MINCLE pathway as a potential therapeutic target in MS. [ABSTRACT FROM AUTHOR]