Two male siblings with a novel LRBA mutation presenting with different findings of IPEX syndrome

INTRODUCTION: LPS-responsive beige-like anchor (LRBA) protein deficiency is a disease of immune dysregulation with autoimmunity affecting various systems. CASE PRESENTATION: Two male siblings with a novel LRBA mutation had different primary findings at admission: the younger sibling had chronic early-onset diarrhoea and the elder one had autoimmune haemolytic anaemia. During long-term follow-up for IPEX phenotype, both developed hypogammaglobulinaemia, enteropathy and lung involvement. The patients partially responded to immunosuppressive therapies. A homozygous c.2496C>A, p.Cys832Ter (p.C832*) mutation in the LRBA gene causing a premature stop codon was detected. After molecular diagnosis, abatacept, as a target-specific molecule, was used with promising results. CONCLUSION: LRBA deficiency is a recently defined defect, with variable presentations in different patients; a single, definitive treatment option is thus not yet available.