Figure 4.

Brain findings in patients with C-terminal truncating MN1 variants. (A) Inferior cerebellum (axial view): foliar dysplasia with indistinct vermis and abnormal folia crossing the midline (Individuals 2, 14, 17, 20, 21); normal inferior cerebellar anatomy (Individuals 24 and 28). (B) Superior cerebellum (axial view): small (Individuals 17, 20 and 21) or almost absent (Individuals 2 and 14) vermis with abnormal folia crossing the midline especially ventrally; normal superior cerebellar anatomy with intact vermis (Individuals 24 and 28). Arrow in Individual 17 indicates persistent trigeminal artery. (C) Insula (axial view): polymicrogyria interior to yellow bars (Individuals 14, 17, 20 and 21), normal appearance (Individuals 2, 24 and 28). Note that Individual 14 has a cavum velum interpositum (asterisk) and all individuals with C-terminal truncating variants have unusual head shape with bitemporal narrowing. (D) Midline (sagittal view): Tall, flat forehead and thickened rostral corpus callosum (Individuals 2, 14, 17, 20 and 21), abnormal vermis lobulation with indistinct primary and horizontal fissures (Individuals 2, 14, 17, 20 and 21), persistent trigeminal artery (arrow in Individual 14) and prominent posterior clinoid process (arrowheads in Individuals 17 and 20).