Transient immune deficiency accompanied with homozygous CBL rare variant

Pediatr Int. 2023 Jan;65(1):e15439. doi: 10.1111/ped.15439.

Abstract

Background: A critical role in cellular proliferation is played by Casitas B-lineage Lymphoma proto-oncogene (CBL). Germline heterozygous CBL variants give rise to CBL syndrome, which is phenotypically similar to RASopathy. Somatic mutations in CBL have been reported in patients with juvenile myelomonocytic leukemia (JMML).

Methods: Exome analysis was performed in a patient with immunodeficiency who developed Pneumocystis jirovecii pneumonia.

Results: Exome analysis identified a homozygous CBL missense variant. Cell biological analysis of this CBL variant confirmed attenuated function.

Conclusion: Spontaneous regression of hematological proliferation has been observed in patients with CBL-mutated JMML and in patients with CBL syndrome. Intriguingly, immunological impairment was spontaneously ameliorated by aging in this patient.

Keywords: CBL; immunodeficiency; transient.

MeSH terms

  • Germ-Line Mutation
  • Homozygote
  • Humans
  • Immunologic Deficiency Syndromes* / complications
  • Immunologic Deficiency Syndromes* / diagnosis
  • Immunologic Deficiency Syndromes* / genetics
  • Leukemia, Myelomonocytic, Juvenile* / complications
  • Leukemia, Myelomonocytic, Juvenile* / genetics
  • Mutation
  • Mutation, Missense