Immunodeficiency Is A Tough Nut to CRAC: The Importance of Calcium Flux in T Cell Activation

Table 2.

Defects in Other Lymphocyte-Specific Genes Leading to SCID^a

		*Lymphocytes Present*
*Disease*	*Genetic defect*	*T cells*	*B cells*
^a Mutations, in some instances, may allow partial expression and function of certain immune cell lineages.
^b Absent or decreased numbers of CD8⁺ T cells with normal numbers of CD4⁺ T cells.
CD3γ/CD3ε deficiency	Defective transcription of CD3D and CD3E genes	+	+
CD8 deficiency	Mutation in CD8A gene	−^b	+
ZAP-70 deficiency	Mutation in ZAP-70 kinase gene	−^b	+
MHC II deficiency	Mutation in transcription factors for MHC II	−^b	+
TAP 1/2 deficiency	Mutation in TAP 1/2 genes: MHC I deficiency	−^b	+
X-linked hyper-IgM	Mutation in CD40 ligand gene: Defective B cells	+	+/−
CD40 deficiency	Mutation in CD40 ligand gene: Defective B cells	+	+/−
ORAI1 deficiency	Mutation in ORAI1 gene: Defective Ca²⁺ influx in T cells	+	+