Figure 1.
(A) Axial T2-weighted MRI showing collateral formation near the brainstem (arrow). (B) Axial magnetic resonance time-of-flight (MR TOF) angiography demonstrating occlusion of bilateral medial and anterior cerebral arteries (arrows). (C) MR TOF angiography demonstrating occlusion of bilateral medial and anterior cerebral arteries (top, sagittal) and patent vertebral and basilar arteries (bottom, coronal). (D) Protein map of the SAMHD1 variants identified in our patient and reported in AGS patients with MMD and/or intracerebral large artery disease. (E) Sanger sequencing of the variants identified in our patient. (F) Increased interferon responsive gene expression is demonstrated in patient samples collected three weeks apart, consistent with biallelic SAMHD1 variants.