ABSTRACT
A severe and chronic deficiency of vitamin E (alpha-tocopherol) is associated with a characteristic neurological syndrome with typical "clinical," neuropathological, and electrophysiological abnormalities in both humans and experimental animals. Repletion of vitamin E-deficient human subjects with alpha-tocopherol typically halts the progression of the neural signs and symptoms, and in some cases, can result in objective improvement. Electrophysiological parameters provide an objective measure of neural and visual function and improvement of some of these measures has been reported after repletion with vitamin E in humans. In this longitudinal study, the effects of repleting rats with a diet containing 36 mg/kg all-rac-alpha-tocopheryl acetate for 20 wk after they had been receiving a vitamin E-deficient diet for 38 wk was studied. We report significant improvements in growth and a number of electrophysiological parameters of both neural and visual function after repletion. These results confirm the validity of the vitamin E-deficient rat as a model of vitamin E deficiency in humans.
Subject(s)
Neurons/physiology , Vitamin E Deficiency/physiopathology , alpha-Tocopherol/pharmacology , Animals , Disease Models, Animal , Disease Progression , Electrophysiology , Electroretinography , Evoked Potentials, Somatosensory/physiology , Evoked Potentials, Visual/physiology , Longitudinal Studies , Male , Neural Conduction/physiology , Neurons/drug effects , Rats , Rats, Wistar , Reproducibility of Results , Vitamin E Deficiency/drug therapy , alpha-Tocopherol/administration & dosage , alpha-Tocopherol/therapeutic useABSTRACT
We describe the clinical features of a new syndrome causing hyperinsulinism in infancy (HI), severe enteropathy, profound sensorineural deafness, and renal tubulopathy in three children born to two pairs of consanguineous parents. This combination of clinical features is explained by a 122-kb contiguous gene deletion on the short arm of chromosome 11. It deletes 22 of the 39 exons of the gene coding for the SUR1 component of the KATP channel on the pancreatic beta-cell thereby causing severe HI. It also deletes all but two of the 28 exons of the USH1C gene, which causes Usher syndrome and is important for the normal development and function of the ear and the eye, the gastrointestinal tract, and the kidney, thereby accounting for the symptoms of deafness, vestibular dysfunction and retinal dystrophy seen in type 1 Usher syndrome, diarrhoea, malabsorption, and tubulopathy. This contiguous gene deletion provides important insights into the normal development of several body organ systems.
