Fig. 1.

CDC42 protein structure, pedigree, and transcript information, prediction and zygosity. A The CDC42 p.Lys16Glu variant (red outline) results in a substitution of the positively charged lysine (position 16) for a negatively charged glutamic acid [24]. Other CDC42 variants (modified from [10]) are marked by color depending on the phenotypic group: Variants belonging to phenotypic group I are marked in yellow, group II in green, group III in blue, and group IV in purple. The variants reported to be associated with T and B cell defect are marked in bold. All variants above the protein structure are missense variants,the variant below is a read through variant. B Pedigree of the index patient P1 and her daughter P2. The missense variant in exon 2 of the CDC42 gene was originally identified in P2 through newborn screening and was subsequently found in her mother P1, in the latter albeit as mosaic of ~ 50% in whole blood and ~ 20% in CD3 T cells (indicated by black dots). The variant was not detected in the grandmother nor in the grandfather and was thus de novo in the mother. C Information on gene variant and predictions. D CDC42 protein expression in PBMCs from three healthy controls (HC1-3), P1 and P2, and quantification of expression levels of CDC42 relative to GAPDH in PBMCs from two independent blood draws per patient. GAPDH was used as loading control