Genetic analysis. (A) DNA sequence analysis in PBMCs from a healthy control (wild type) and various cell populations from the patient obtained either by buccal swab, Ficoll separation (granulocytes), or flow cytometric cell sorting. The wild-type (left) and mutated nucleotide (right) sequences and the resulting amino acid change are shown below. (B) Location of the changed amino acid in a model of the IL-2 receptor with its bound ligand as calculated with the SWISS-MODEL software (The Swiss Institute of Bioinformatics). Brown indicates γ chain; green, β chain; blue, α chain; and purple, IL-2.