Genetic loci contributing to hemophagocytic lymphohistiocytosis do not confer susceptibility to systemic-onset juvenile idiopathic arthritis

OBJECTIVE To investigate whether single-nucleotide polymorphisms (SNPs) within the genes PRF1, GZMB, UNC13D, and Rab27a, which are involved in natural killer cell dysfunction and known to contribute to the risk of hemophagocytic lymphohistiocytosis (HLH), confer an increased risk of susceptibility to systemic-onset juvenile idiopathic arthritis (JIA). METHODS Four SNPs across the PRF1 gene locus, 5 for GZMB, 7 for UNC13D, and 11 for Rab27a were investigated using MassArray genotyping in 133 UK Caucasian patients with systemic-onset JIA and 384 ethnically matched unrelated control subjects. Additional control genotypes were accessed from the data generated by the Wellcome Trust Case Control Consortium. RESULTS No significant association was found between any SNP within the 4 selected loci and systemic-onset JIA, by either single-point or haplotype analysis. CONCLUSION The results of this study demonstrate that genes involved in HLH do not confer a significant risk of association with systemic-onset JIA.