Enhanced T cell activation in ORAI1 mutant patient. scRNA-seq of PBMC from the ORAI1 mutant patient and three HD controls combined. (A) Violin plots for quality control metrics for each sample after filtering and integration. UMI, unique molecular identifier. (B) Aggregate UMAP plot of immune cell subsets identified in 15,000 PBMC from the patient and three controls. (C) Heatmap of conserved canonical marker genes of seven distinct major immune cell subsets. (D) Volcano plots of DEGs in the patient and three HD controls for each identified cell type. (E) Upset plot of the overlap between DEGs in different cell types and a Venn diagram representing the corresponding overlap between CD4⁺ and CD8⁺ T cells. (F and G) Top 20 dysregulated pathways based on DEGs in the patient and HD controls using the IPA platform in CD4⁺ T cells (F) and CD8⁺ T cells (G). (H) Top 10 upregulated Hallmark pathways in NK cells of the patient. Z scores in C were calculated using the normalized average expression per cell in each cell type across all samples. Statistical analysis in D was performed using a Wilcoxon rank sum test. Genes in E were considered significant if the P_adj was <0.05. The significance of pathways shown in F–H was calculated using right-tailed Fisher’s exact test. The significance in D, F, and G was adjusted using the Benjamini–Hochberg method.