title: Ocular manifestations in the X-linked intellectual disability syndromes.
abstract: Intellectual disability (ID), a common neurodevelopmental disorder characterized by limitations of both intellectual functioning and adaptive behavior, affects an estimated 1-2% of children. Genetic causes of ID are often accompanied by recognizable syndromal patterns. The vision apparatus is a sensory extension of the brain, and individuals with intellectual disabilities frequently have coexisting abnormalities of ocular structures and the visual pathway system. About one-third of the X-linked intellectual disability (XLID) syndromes have significant eye or ocular adnexa abnormalities that provide important diagnostic clues. Some XLID syndromes (e.g. Aicardi, cerebrooculogenital, Graham anophthalmia, Lenz, Lowe, MIDAS) are widely known for their characteristic ocular manifestations. Nystagmus, optic atrophy, and strabismus are among the more common, nonspecific, ocular manifestations that contribute to neuro-ophthalmological morbidity. Common dysmorphic oculofacial findings include anophthalmia, microphthalmia, hypertelorism, and abnormalities in the configuration or orientation of the palpebral fissures. Four XLID syndromes with major ocular manifestations (incontinentia pigmenti, Goltz, MIDAS, and Aicardi syndromes) are notable because of male lethality and expression occurring predominantly in females. The majority of the genes associated with XLID and ocular manifestations have now been identified.
authors.affiliation: a Department of Ophthalmology , University of North Carolina School of Medicine , Chapel Hill , North Carolina , USA.|b Division of Genetics and Metabolism, Department of Pediatrics , University of North Carolina School of Medicine , Chapel Hill , North Carolina , USA.
authors.forename: Natario L
authors.identifier: 0000-0001-8713-2097
authors.initials: NL
authors.lastname: Couser
authors.affiliation: c University of North Carolina School of Medicine , Chapel Hill , North Carolina , USA.
authors.forename: Maheer M
authors.initials: MM
authors.lastname: Masood
authors.affiliation: b Division of Genetics and Metabolism, Department of Pediatrics , University of North Carolina School of Medicine , Chapel Hill , North Carolina , USA.|d Department of Genetics , University of North Carolina School of Medicine , Chapel Hill , North Carolina , USA.
authors.forename: Arthur S
authors.initials: AS
authors.lastname: Aylsworth
authors.affiliation: e Greenwood Genetic Center, JC Self Research Institute of Human Genetics , Greenwood , South Carolina , USA.
authors.forename: Roger E
authors.initials: RE
authors.lastname: Stevenson
mesh_terms: D005124:Eye Abnormalities / Q000175:diagnosis* / Q000235:genetics; D005128:Eye Diseases / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D050172:Genes, X-Linked; D006801:Humans; D008297:Male; D038901:X-Linked Intellectual Disability / Q000175:diagnosis* / Q000235:genetics
keywords: Aicardi syndrome; Goltz syndrome; Graham anophthalmia syndrome; Lenz syndrome; Lowe syndrome; MIDAS syndrome; X-linked intellectual disability (XLID); cerebrooculogenital syndrome; incontinentia pigmenti; ocular abnormalities