Relationship of monocyte BTK expression profiles between XLA patients and their mothers. Each histogram represents analysis of CD14⁺ monocytes. The solid and dashed lines indicate the staining with anti-BTK and control antibodies, respectively. Five thousand cells were evaluated in each gated population. (A) The patient had the complete BTK deficiency, and the mother showed the mosaic BTK expression (eg, family 13). (B) The patient had the complete BTK deficiency, but the mother showed the single-positive BTK expression (eg, family 14). (C) The patient had the partial BTK deficiency, and the mother showed the mosaic BTK expression with dimly BTK⁺ cells and brightly BTK-expressing cells (eg, family 7). (D) Both the patient and the mother expressed the normal BTK expression (eg, family 6). The frequency (no. of families/total no. of families) is depicted below the histogram.