Mannose-Binding Lectin2 gene polymorphism in PANDAS patients

Introduction: Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), a subgroup of obsessive-compulsive disorder (OCD), has received much attention even though the specific underlying mechanisms remain unknown. Mannose-binding lectin (MBL) is a key factor in the innate immune response. The aim of this study was to investigate the role of MBL2 gene polymorphisms in pediatric OCD patients diagnosed as PANDAS, PANDAS-Variant and non-PANDAS. Methods: The study included 102 pediatric OCD patients (59 [57.8% ] PANDAS, 20 [19.6% ] non-PANDAS, and 23 [22.5% ] PANDAS-Variant) and 60 healthy controls. Polymorphisms at codon 52, 54 and 57 of the MBL2 gene were investigated. Results: Codon 54 polymorphism and any variant of MBL2 gene were significantly more frequent in the OCD group than in the control group (OR=2.97, 95% CI: 1.26-6.97; and OR=2.66, 95% CI: 1.32-5.38, respectively). According to regression analysis, the presence of any variant of MBL2 gene was found in 14.50-fold increased frequency in the PANDAS subgroup compared with the non-PANDAS subgroup (95% CI: 2.49-84.19). Conclusions: Our findings support an association between MBL2 genotypes and pediatric OCD, particularly PANDAS-OCD.