Aprosencephaly And Cerebellar Dysgenesis

Florell et al. (1996) described the association of aprosencephaly, absence of optic chiasm (with well-formed eyes and retinal dysplasia), absent mesencephalon, poorly formed metencephalon, and severely dysplastic cerebellum in 2 sibs with first-cousin parents. The male fetus had wide gums and pes equinovarus, and the female fetus had bifid uvula. No visceral abnormalities were evident. Florell et al. (1996) noted that these types of abnormalities are consistent with mutation of a gene involved in specific spatiotemporal expression in forebrain development. Although maldevelopment of the prosencephalon, mesencephalon, and rostral rhombencephalon matched the expression profile of the OTX2 gene (600037), no sequence variations of the OTX2 gene were identified. Involvement of the mesencephalon and rhombencephalon and the absence of visceral and axial limb abnormalities distinguish this presumably autosomal recessive syndrome from the XK aprosencephaly syndrome (207770).