Subcortical band heterotopia and lissencephaly pedigree demonstrating an X-linked allele

(A) Pedigree in which a mother with subcortical band heterotopia (I-1), has a daughter with subcortical band heterotopia (II-2), and a son with classical lissencephaly (II-1). The husband is unaffected (I-2) (Pedigree described by Berg and colleagues) (Berg MJ, Schifitto G, Powers JM, et al. X-linked female band heterotopia-male lissencephaly syndrome. Neurology 1998;50:1143-6.). (B) Pedigree in which a mother with subcortical band heterotopia (I-2) has children with three different males (I-1, I-3, I-4), and with each partner there is a child with a migrational defect. With the first partner (I-4), there is a girl with subcortical band heterotopia (II-5); with the second partner (I-3), there is a girl with subcortical band heterotopia (II-4); and with the third partner (I-1), there is a set of unaffected identical male twins (II-2 and II-3) and a son with lissencephaly (II-1) (One of two pedigrees described by Pinard and colleagues) (Pinard JM, Motte J, Chiron C, Brian R, Andermann E, Dulac O. Subcortical laminar heterotopia and lissencephaly in 2 families: a single X linked dominant gene. J Neurol Neurosurg Psychiatry 1994;57:914-20.). (Contributed by Dr. Joseph Gleeson.)