AN ATYPICAL PRESENTATION OF LIPOPOLYSACCHARIDE-RESPONSIVE BEIGE-LIKE ANCHOR PROTEIN DEFICIENCY

Abstract

<h3>Introduction</h3> Lipopolysaccharide-responsive beige-like anchor (LRBA) protein deficiency is associated with diarrhea, autoimmune disorders, organomegaly, recurrent infections, hypogammaglobulinemia, chronic lung manifestations, and growth retardation. However, LRBA mutations show a wide range of phenotypic variability. We present a case of a sixteen-year-old girl with a variant of uncertain significance (VUS) in the LRBA gene with atypical symptoms of LRBA deficiency. <h3>Case Description</h3> The patient is a sixteen-year-old female with type one diabetes mellitus, chronic urticaria, and idiopathic anaphylaxis requiring admission. Her complete blood count with differential, B and T cell phenotyping, and immunoglobulin levels were normal. She failed high dose antihistamines and omalizumab. Due to atypical symptoms, including soft tissue swelling, joint pains, recurrent abdominal pain, and elevated interleukin 10, interleukin 6, and S100 during an episode, we obtained an auto-inflammatory panel that showed a heterozygous VUS mutation in the LRBA gene. Parental LRBA testing showed the variants were trans-acting, increasing the likelihood that the variants contribute to her phenotype. She was started on abatacept with hydroxychloroquine, which improved her symptoms. <h3>Discussion</h3> This case highlights an atypical presentation of LRBA deficiency presenting with chronic urticaria and idiopathic anaphylaxis with a normal immune work up, symptoms of which are responsive to abatacept and hydroxychloroquine.