A novel IL2RG mutation associated with maternal T lymphocyte engraftment in a patient with severe combined immunodeficiency.

Severe combined immunodeficiency (SCID) represents a genetically heterogeneous group of primary immunodeficiency disorders. Irrespective of the genetic defect, patients with SCID may be engrafted with transplacentally derived maternal T-lymphocytes that in a subset of cases may be responsive to phytohemagglutinin. Here, we present, from a genetic perspective, an SCID patient who not only harbored a novel mutation in the gene encoding the common gamma chain (gamma c) of the IL-2 receptor (IL2RG), but also carried reactive maternal T lymphocytes that produced a karyotype that was initially perplexing.