Co-occurrence of MEN1 p.Gly111fs and AIP p.Arg16His variants in familial MEN1 phenotype

Background/Aim: Familial multiple endocrine neoplasia type 1 (MEN1) is a rare disorder mostly associated with germline MEN1 mutations. Materials and Methods: Genotyping of the MEN1, cyclin-dependent kinase inhibitor 1B (CDKN1B) and aryl hydrocarbon receptor-interacting protein (AIP) genes using Sanger sequencing was carried out in a family with MEN1 and the resulting germline variants genotyped in an additional 95 ethnically matched controls. Results: A missense variant in AIP (p.Arg16His) gene and a truncating mutation (p.Gly111fs*8) in MEN1 gene were both detected in the proband and his father, showing limited co-segregation with phenotype. p.Arg16His AIP missense variant was detected in one control. Conclusion: There are conflicting data regarding the functional effects of AIP p.Arg16His and its role in disease development. We demonstrated the co-occurrence of p.Arg16His AIP missense variant in a patient with a bona fide MEN1 mutation. Our finding of p.Arg16His AIP in one of the 95 controls and its co-occurrence with MEN1 in a patient suggests that it is more likely that this variant is a rare polymorphism, unrelated to MEN1 pathogenesis.