1. A genetic factor for age-related cataract: identification and characterization of a novel galactokinase variant, "Osaka," in Asians.
- Author
-
Okano Y, Asada M, Fujimoto A, Ohtake A, Murayama K, Hsiao KJ, Choeh K, Yang Y, Cao Q, Reichardt JK, Niihira S, Imamura T, and Yamano T
- Subjects
- Adult, Age of Onset, Aging pathology, Aging physiology, Alleles, Amino Acid Substitution genetics, Animals, Base Sequence, COS Cells, Cataract enzymology, Cataract metabolism, Child, Preschool, Female, Galactose blood, Galactose metabolism, Gene Frequency genetics, Genetic Testing, Humans, Infant, Infant, Newborn, Japan epidemiology, Kinetics, Korea epidemiology, Male, Middle Aged, Molecular Sequence Data, Pedigree, Asian People genetics, Cataract epidemiology, Cataract genetics, Galactokinase genetics, Genetic Variation genetics, Mutation genetics
- Abstract
Galactokinase (GALK) deficiency is an autosomal recessive disorder characterized by hypergalactosemia and cataract formation. Through mass screening of newborn infants, we identified a novel and prevalent GALK variant (designated here as the "Osaka" variant) associated with an A198V mutation in three infants with mild GALK deficiency. GALK activity and the amount of immunoreactive protein in the mutant were both 20% of normal construct in expression analysis. The K(m) values for galactose and ATP-Mg(2+) in erythrocytes with homozygous A198V were similar to those of the healthy adult control subjects. A population study for A198V revealed prevalences of 4.1% in Japanese and 2.8% in Koreans, lower incidence in Taiwanese and Chinese, no incidence in blacks and whites from the United States, and a significantly high frequency (7.8%; P < .023) in Japanese individuals with bilateral cataract. This variant probably originated in Japanese and Korean ancestors and is one of the genetic factors that causes cataract in elderly individuals.
- Published
- 2001
- Full Text
- View/download PDF