CHRONIC EPSTEIN-BARR VIRUS INFECTION DUE TO A GAIN-OF-FUNCTION MUTATION OF THE PIK3CD GENE: A CASE REPORT AND LITERATURE REVIEW

Abstract

Objective To investigate the clinical manifestations and gene mutation characteristics of chronic Epstein-Barr virus (EBV) infection caused by a gain-of-function (GOF) mutation of the PIK3CD gene through a case report. Methods The clinical data of a pediatric patient was collected, and whole-exome sequencing was used to detect gene mutations. Related articles were searched and reviewed. Results The pediatric patient experienced recurrent respiratory infection since 2 years of age accompanied by enlargement of liver, spleen, and lymph nodes and recurrent varicella-like rash. There was a significant increase in the serum level of EBV antibody, and lymphoid tissue biopsy showed T lymphocyte proliferative changes and positive EBV-encoded RNA. At the age of 13 years, the pediatric patient experienced a significant increase in the level of immunoglobulins in blood with various positive autoantibodies. Genetic testing revealed a heterozygous mutation in the PIK3CD gene, c.3061G>A(p.E1021K), and literature review showed that this mutation was a GOF mutation. Conclusion The GOF mutation of the PIK3CDgene can lead to susceptibility to EBV and chronic EBV infection, with the clinical manifestations of lymphoid hyperplasia and characteristic rash. Pediatric patients with this disease can also present with significant increases in the levels of immunoglobulins in blood, which may be associated with the formation of massive autoantibodies caused by autoimmune response.

Keywords

• pik3cd gene|activated pi3k-delta syndrome|gain of function mutation|epstein-barr virus infection|whole exome sequencing|signs and symptoms|mutation