Major histocompatibility complex (MHC) class II deficiency is a primary immunodeficiency disease characterized by abnormality of MHC class II molecules surface expression on peripheral blood lymphocytes and monocytes. Clinical manifestations include extreme susceptibility to viral, bacterial, and fungal infections but the immunodeficiency is not as severe as SCID (severe combined immunodeficien...

In Manitoba, Canada, the overall incidence of Severe Combined Immunodeficiency (SCID) is three-fold higher than the national average, with SCID overrepresented in two population groups: Mennonites and First Nations of Northern Cree ancestries. T-cell receptor excision circle (TREC) assay is being used increasingly for neonatal screening for SCID in North America. However, the majority of SCID p...