Effect of the TUBB1 p.Gly109Glu variant in CD34⁺ peripheral blood cell–derived MK cultures. (A) Representative images of CD34⁺ peripheral blood cell–derived MKs in 2 controls and in homozygous carriers (pedigree I) of the novel variant p.Gly109Glu. (B) Detailed images of spread MKs. MKs were labeled with β1-tubulin (green) and rhodamine-phalloidin (red). Nuclei were stained with DAPI (blue). Images were acquired in a Carl Zeiss Axio Observer.A1 fluorescence microscope with a 63× objective lens. Scale bars are 5μm. (C) Classification of MKs (as described in Figure 3; ^#P < .05) in homozygous carriers and controls. (D) Microtubule length in MKs from controls and homozygous carriers of the p.Gly269Asp β1-tubulin variant was assessed using ImageJ software. Values are mean ± SD of values obtained from at least 6 different microscopy fields. *P < .05.