S G Crewther1, P M Kiely, L L Kok, D P Crewther. 1. School of Psychological Science, La Trobe University, Bundoora, Victoria, Australia. s.crewther@latrobe.edu.au
Abstract
BACKGROUND: Subjects with velo-cardio-facial syndrome (VCFS) were assessed to determine whether the learning disabilities (LDs) characterizing the syndrome are compounded by visual function deficits, which would be predicted on the basis of the proposed embryonic derivation of the genetic anomaly. METHODS: Twelve subjects diagnosed with VCFS underwent a vision screening with emphasis on binocular function. RESULTS: Subjects exhibited deficits in accommodation (N = 5), convergence (N = 7), fusional reserves (N = 9), and stereopsis (N = 10). Three patients were strabismic at near. No patient was in the clinically normal range for all tests of binocular function. CONCLUSIONS: Individuals with VCFS have a chromosome 22 deficit thought to alter the migration of neural crest (NC) cells, which are the embryonic precursors of the autonomic innervation of the smooth muscle components of the eye and of cranial nerves III, IV, and VI. It was predicted that VCFS patients would demonstrate reduced accommodation and convergence flexibility, which would reduce visual comfort for near work. The pathological etiology of the visual anomalies suggests that if visual training is not successful, these patients should be provided with a suitable optical reading correction from an early age.
BACKGROUND: Subjects with velo-cardio-facial syndrome (VCFS) were assessed to determine whether the learning disabilities (LDs) characterizing the syndrome are compounded by visual function deficits, which would be predicted on the basis of the proposed embryonic derivation of the genetic anomaly. METHODS: Twelve subjects diagnosed with VCFS underwent a vision screening with emphasis on binocular function. RESULTS: Subjects exhibited deficits in accommodation (N = 5), convergence (N = 7), fusional reserves (N = 9), and stereopsis (N = 10). Three patients were strabismic at near. No patient was in the clinically normal range for all tests of binocular function. CONCLUSIONS: Individuals with VCFS have a chromosome 22 deficit thought to alter the migration of neural crest (NC) cells, which are the embryonic precursors of the autonomic innervation of the smooth muscle components of the eye and of cranial nerves III, IV, and VI. It was predicted that VCFSpatients would demonstrate reduced accommodation and convergence flexibility, which would reduce visual comfort for near work. The pathological etiology of the visual anomalies suggests that if visual training is not successful, these patients should be provided with a suitable optical reading correction from an early age.
Authors: Emma N M M von Scheibler; Emy S van der Valk Bouman; Myrthe A Nuijts; Noël J C Bauer; Tos T J M Berendschot; Pit Vermeltfoort; Levinus A Bok; Agnies M van Eeghen; Michiel L Houben; Thérèse A M J van Amelsvoort; Erik Boot; Michelle B van Egmond-Ebbeling Journal: Am J Med Genet A Date: 2021-11-12 Impact factor: 2.578