Primary immunodeficiency or monogenic inflammatory bowel disease

Gene: PAX5

Red List (low evidence)

Kaiser et al. described 1 patient from 1 kindred, harboring compound heterozygous mutations in the PAX5 gene (p.R31Q / p.E242*). They presented with early-onset recurrent infections, severe hypogammaglobulinemia, a profound reduction of peripheral B cells, severely impaired sensorimotor learning, and autism spectrum disorder (ASD).
The underlying mechanism and phenotype were extensively validated using a patient-specific in vivo mutant mouse model (Pax5R31Q/E242* and Pax5R31Q/- mice). These animal models successfully recreated both the immunological and neurological phenotypes, demonstrating an early B-cell developmental block (arrest at the pro-B to pre-B transition), reduced B cell counts in the bone marrow, aberrant cerebellar foliation, and behavioral deficits across ASD domains. Flow cytometry analysis of both the patient's peripheral blood and the murine models confirmed the severe reduction in total B cell numbers and immune arrest. Complete knockout models (Pax5E242*/E242*) demonstrated an absolute failure to generate bone marrow B cells.
Sources: Literature

Created: 17 Jun 2026, 4:13 p.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
hypogammaglobulinemia; reduced B cells; sensorimotor deficits; autism spectrum disorder

Publications

• 35947077