Subject(s)
Eye Diseases, Hereditary/diagnosis , Night Blindness/diagnosis , Ocular Physiological Phenomena , Retinal Rod Photoreceptor Cells/pathology , Dark Adaptation , Electroretinography , Eye Diseases, Hereditary/physiopathology , Female , Humans , Middle Aged , Night Blindness/physiopathology , Retinal Cone Photoreceptor Cells/physiology , Visual AcuityABSTRACT
Intracellular calcium ([Ca2+]i) is highly regulated in eukaryotic cells. The free [Ca2+]i is approximately four orders of magnitude less than that in the extracellular environment. It is, therefore, an electrochemical gradient favoring Ca2+ entry, and transient cellular activation increasing Ca2+ permeability will lead to a transient increase in [Ca2+]i. These transient rises of [Ca2+]i trigger or regulate diverse intracellular events, including metabolic processes, muscle contraction, secretion of hormones and neurotransmitters, cell differentiation, and gene expression. Hence, changes in [Ca2+]i act as a second messenger system coordinating modifications in the external environment with intracellular processes. Notably, information on the molecular genetics of the membrane channels responsible for the influx of Ca2+ ions has led to the discovery that mutations in these proteins are linked to human disease. Ca2+ channel dysfunction is now known to be the basis for several neurological and muscle disorders such as migraine, ataxia, and periodic paralysis. In contrast to other types of genetic diseases, Ca2+ channelopathies can be studied with precision by electrophysiological methods, and in some cases, the results have been highly rewarding with a biophysical phenotype that correlates with the ultimate clinical phenotype. This review outlines recent advances in genetic, molecular, and pathophysiological aspects of human Ca2+ channelopathies.
Subject(s)
Calcium Channels/metabolism , Calcium/metabolism , Channelopathies/physiopathology , Animals , Calcium Channels/chemistry , Calcium Channels/classification , Calcium Channels/genetics , Channelopathies/genetics , Disease Models, Animal , Genetic Diseases, X-Linked/genetics , Genetic Diseases, X-Linked/physiopathology , Genetic Predisposition to Disease , Humans , Hypokalemic Periodic Paralysis/genetics , Hypokalemic Periodic Paralysis/physiopathology , Malignant Hyperthermia/genetics , Malignant Hyperthermia/physiopathology , Mutation , Night Blindness/genetics , Night Blindness/physiopathology , Phylogeny , Protein Conformation , Spinocerebellar Ataxias/genetics , Spinocerebellar Ataxias/physiopathology , Spinocerebellar Degenerations/genetics , Spinocerebellar Degenerations/physiopathologyABSTRACT
Se presenta el estudio clínico y genético de una familia (cinco casos) con Síndrome de Goldmann-Favé. Cuatro pacientes son del sexo femenino y uno masculino: Todos con disminución de la agudeza visual bilateral, con nictalopia reportada desde la primera década de la vida, presencia de catarata subcapsular posterior en algunos de ellos; así como desprendimiento de retina en tres pacientes. En la exploración al fondo de ojo se encontró licuefacción vítrea y datos de retinosis pigmentaria.