APDS in a 3-year-old boy presenting with EBV viremia and hodgkin lymphoma associated with a novel germline heterozygous variant in PIK3CD and with characteristic immune phenotype but no upregulation of the T cell mTOR pathway

We describe a 3-year-old patient with a novel variant in the PIK3CD gene (c.58G > A p.(Val20lle)) presenting with EBV viremia, Hodgkin lymphoma, upregulation T follicular helper cells and CD10 + B cells consistent with a phenotype of APDS in a 3-year-old boy. This case broadens our understanding of the genetic and phenotypic spectrum of PIK3CD gene mutations in APDS.