Bone marrow abnormalities in patients with ADA-SCID. (A) Hypocellular biopsy from patient ADA1 at 21 years of age. (B) Left-shifted eosinophilia in patient ADA6. (C) Atypical, mononuclear megakaryocytes in a clot section from patient ADA16. (D) Dysplastic megakaryocyte with separated nuclear lobes in patient ADA6. (E) Area of atypical fibrosis in the marrow biopsy of patient ADA10. (F) Hypogranular granulocytic precursor and megaloblastoid erythroid precursor (arrows) in the marrow aspirate of patient ADA10. Biopsies were stained with hematoxylin and eosin and aspirates with Wright-Giemsa. Images were obtained via digital microscopy using an Olympus BX-51 microscope equipped with a DPlan 40×/0.65 numeric aperture objective and captured using an Olympus DP70 digital camera system. Adobe Photoshop CS3 was used to assemble the panels into one figure. (A,E) Original magnification ×40. (B,D,F) Original magnification ×1000. (C) Original magnification ×200.