Family and biology studies supporting GNE pathobiology.(A) Family pedigrees. Each family is represented by the designation F1-3. Patients P1 through P9 are shown as black circles (female) and squares (males), whereas unaffected family members are shown as open symbols. Blue boxes refer to potentially affected individuals, but no blood counts were done. Red boxes/circles represent affected individuals. F1 pedigree: The common ancestor “a” died of posttrauma bleeding, whereas “b” died at the age of 2 years from an intracranial hemorrhage. Parents of patients have normal platelet counts and morphology. F2 pedigree, F3 pedigree: “c” refers to an egg donor. (B) A representative hematoxylin and eosin peripheral smear from a patient. Arrows indicate large platelets. (Original magnification, ×60; hematoxylin and eosin stain). (C) Transmission electron microscopy images of platelets isolated from control and indicated patients. Likely dilated open canalicular membrane system that engulfed some debris is shown by the arrows. Bar shown indicates image size. (D) Comparison of percentage of platelets (by FSC/SSC and expression of CD42) that are CD42b low expressing in patients vs heterozygous carriers and unaffected controls. n = 5 patients, 4 heterozygous family members, and 4 unrelated controls. **P = .002 vs control. (E) Fluorescence-activated cell sorter analysis of platelet sialylation levels demonstrating loss of sialylation in platelets from patients with GNE variants. ***P < .001 vs control for MAL. (F) Fluorescence-activated cell sorter analysis of total platelet population on F1 patients (P1 through P5), an obligate F1 carrier (father of P2-P4), and 3 nonaffected controls showing staining for thiazole orange. For panels D and F, graphs show mean ± 1 standard deviation. ***P < .02 comparing affected patients with control patients by Student t test. MAL, maackai amurensis lectin II; SNA/EBL, sambucus nigra lectin; WT, wild type.