Additionally, patients with SMS and those with a c.204insATNFRSF13B mutation display normal regulatory T-cell function and peripheral B-cell tolerance.
In patients with SMS with only 1 TACI allele, we found decreased B-cell extracellular and intracellular expression of TACI, reduced binding of a proliferation-inducing ligand, and decreased TACI-induced expression of activation-induced cytidine deaminase mRNA, but these were normal for cells from patients with SMS and 2 TACI alleles.