PIK3R1 mutation associated with primary immunodeficiency: a case of a 14-year-old male and review of the literature: case report

Abstract

We report a rare case of a 14-year-old boy diagnosed with Activated phosphoinositide 3-kinase delta syndrome Type 2 (APDS2). Based on a typical clinical presentation (Delayed teething, Prominent lymphadenopathy and recurrent characteristic infections started early in life and including multiple episodes of bilateral conjunctivitis, an extensive herpes skin infection in addition to recurrent upper sinopulmonary infections) along with suggestive laboratory immunological findings, and positive confirmatory genetic testing. After diagnosis, the patient was commenced on prophylactic antibiotics which resulted in a reduction in the frequency of his infections and hospitalizations. The targeted therapy of mTOR inhibition with Sirolimus and the possibility of hematopoietic stem cells transplantation are considered and discussed with the family, and he is on regular follow-up with the Allergy/Immunology team. APDS is a rare but increasingly reported inborn error of immunity. Gain-of-function and loss-of-function mutations in phosphoinositide 3-kinase (PIK3CD (encoding P 110 δ ) and PIK3R1 (encoding p 85 α , p 55 α , a n d p 50 α )) lead to APDS1 and APDS2, respectively. Our aim in reporting our case is to allow room for more elaboration of the different genotypes and clinical presentations of both types of APDS, in which early and accurate diagnosis will subsequently help in the initiation of outcome-improving therapy.