Case#: 15-year-old girl, ethnicity not specified DiseaseAssertion: The patient is asserted to have "CTLA-4 deficiency" FamilyInfo: CasePresentingHPOs: HP:0002315 (Headaches), HP:0002205 (Recurrent respiratory infections), HP:0007359 (Focal-onset seizure), HP:0001744 (Splenomegaly), HP:0002028 (Chronic diarrhea), HP:0005231 (Chronic gastritis), HP:0002875 (Exertional dyspnea), HP:0003139 (Panhypogammaglobulinemia) CaseHPOFreeText: Brain MRI showed multiple inflammatory lesions. CSF analysis showed elevated white cell count and protein levels. Figure 2 provides overview of clinical history and medical management. CaseNotHPOs: CaseNotHPOFreeText: Infectious diseases were excluded, including CMB, EBV, HIV, and mycobacteria. CasePreviousTesting: GenotypingMethod: Patient was tested via a targeted NGS panel. PreviouslyPublished: Not previously published. Variant: The patient harbors the NM_005214.5(CTLA4): c.394G>A (p.Glu132Lys) variant in the heterozygous state. ClinVar: 662200 gnomAD: This variant was not found in gnomAD v4.1.0 SupplementalData: Supplementary Table S1 contains full immunological workup.