ORAI1 is the pore-forming subunit of the calcium release-activated calcium channel
responsible for calcium influx into cells triggered by endoplasmic reticulum store depletion.
We report here a patient with severe combined immunodeficiency and absent store-
operated calcium entry due to a novel mutation in ORAI1 that results in the expression of a C-
terminally truncated protein that abolishes ORAI1 binding to STIM1.