Primary immunodeficiency or monogenic inflammatory bowel disease

Gene: SIT1

Red List (low evidence)

Pu Chen et al. described 1 patient from 1 kindred, harboring homozygous mutations in the SIT1 gene. They presented with combined immune deficiency and recurrent Hodgkin lymphoma. The underlying mechanism and phenotype were validated ex vivo using patient-derived lymphocytes and in vitro using CRISPR-Cas9-mediated SIT1 knockout T cells from healthy donors, demonstrating skewed T cell subsets, increased activation and proliferation, impaired CD8+ cytotoxicity, and defective immune synapse maturation with vesicle accumulation upon T cell receptor stimulation. The phenotype was successfully recreated with complete knockout models.
Sources: Literature

Created: 23 Jun 2026, 9:25 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Combined immunodeficiency; Hodgkin lymphoma; Abnormal T cell physiology; Impaired CD8+ T cell cytotoxicity

Publications

• 42128181