Severe Combined Immunodeficiency (absent T absent B cells)
Gene: PSMB10
ClinGen classification: Limited
Heterozygous germline variants in PSMB10 were first reported in relationship to PSMB10-related severe combined immunodeficiency in 2022 (PMID: 36250618). Reports describe patients that present early in life with T-/B-/natural killer (NK) cell+ severe combined immunodeficiency with some patients also developing Omenn syndrome (PMID:38503300). All cases are reported to arise from heterozygous, likely de novo missense mutations (two mutations across seven cases) that are predicted to result in a dominant-negative impact on the function of the PSMB10 encoded protein, β2i. β2i is a component of the immunoproteasome and thymoproteasome, which are unique proteasomes with altered formation kinetics and antigen processing capabilities compared to the standard proteasome. These missense mutations are hypothesized to alter steric interactions with other components of the proteasome, destabilizing proteasome formation and structure. Studies have shown that these PSMB10 variants likely have an intrinsic impact on the function and survival of thymic epithelial cells (TEC), thymocytes and peripheral lymphocytes (PMID:29654304, 39734035). Of note, bone marrow transplant has not been curative for most patients, supporting the findings that PSMB10 variants impact both the hematopoietic and thymic components of the immune system. A mouse model harboring a heterozygous missense mutation in Psmb10 partially phenocopies the human disease, exhibiting T and B cell lymphopenia and poor antigen-specific T cell function (PMID:29654304). In summary, there is currently limited evidence to support this gene-disease relationship.
This classification was approved by the ClinGen SCID-CID Working Group on 4/17/2025 (SOP Version 11).Created: 14 Aug 2025, 11:10 p.m. | Last Modified: 14 Aug 2025, 11:10 p.m.
Panel Version: 1.8
Six individuals with three de novo missense variants. Individuals presented with T-B-NK± severe combined immunodeficiency (SCID) and clinical features suggestive of Omenn syndrome, including diarrhea, alopecia, and desquamating erythematous rash.
Sources: LiteratureCreated: 2 Apr 2024, 7:22 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Severe combined immunodeficiency, MONDO:0015974, PSMB10-related
Publications
Gene: psmb10 has been classified as Red List (Low Evidence).
Gene: psmb10 has been classified as Green List (High Evidence).
Gene: psmb10 has been classified as Green List (High Evidence).
gene: PSMB10 was added gene: PSMB10 was added to Severe Combined Immunodeficiency (absent T absent B cells). Sources: Literature Mode of inheritance for gene: PSMB10 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: PSMB10 were set to 38503300 Phenotypes for gene: PSMB10 were set to Severe combined immunodeficiency, MONDO:0015974, PSMB10-related Review for gene: PSMB10 was set to GREEN