<unk> , or "dedicator of cytokinesis 8", is a protein involved in regulating the actin skeleton of the cell. It may also be a tumor suppressor, since<unk>  is lost in many cancers and people with<unk>  are prone to developing malignancies. When it is mutated, an incorrect protein is produced, so there is, at most, a trace level of functional<unk>  protein in the cell. There are a variety of loss-of-function mutations in<unk>  that can cause deficiency and hyperimmunoglobulin E, including frameshift mutations, nonsense mutations, microdeletions, and, most commonly, large deletions. The low number of T cells (T cell lymphopenia) and other lymphocytes appears to be responsible for the susceptibility to infections, and the poor humoral immunity is responsible for low response to vaccines. However, how<unk>  is involved in the loss of T cells is not known.
DOCK8 deficiency
ZAP70 deficiency
PMM2 deficiency
WNT4 deficiency
ZC4H2 deficiency
NGLY1 deficiency
Janus kinase 3 deficiency
MECP2 duplication syndrome