Recurrent Infections and Refractory Lymphoproliferation Associated With a Novel PRKCD Variant: A Case Report of Successful Haematopoietic Stem Cell Transplantation.

Lymphoproliferation is a common manifestation of inborn errors of immunity and may delay diagnosis when it is the initial presentation. A nine-year-old girl developed recurrent lymphadenopathy from two years of age, accompanied by recurrent infections, anaemia and growth retardation. Whole-exome sequencing identified a homozygous PRKCD missense variant. Lymph node biopsy revealed florid follicular hyperplasia with cytomegalovirus (CMV) activation, and CMV viremia was detected. Despite immunoglobulin replacement, valganciclovir and immunomodulatory therapy, lymphoproliferation persisted. Haematopoietic stem cell transplantation was successfully performed, highlighting the importance of early genetic diagnosis and timely curative treatment in these patients.