A Genetic Factor for Age-Related Cataract: Identification and Characterization of a Novel Galactokinase Variant, "Osaka," in Asians
A Genetic Factor for Age-Related Cataract: Identification and Characterization of a Novel Galactokinase Variant, "Osaka," in Asians
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Date
2001
Authors
Okano, Yoshiyuki
Asada, Minoru
Fujimoto, Akie
Ohtake, Akira
Murayama, Koichiro
Hsiao, Kwang-Jen
Choeh, Kyuchul
Yang, Yanling
Cao, Qixiang
Reichardt, Juergen KV
Advisor
Citation
Okano, Yoshiyuki and Asada, Minoru and Fujimoto, Akie and Ohtake, Akira and Murayama, Koichiro and Hsiao, Kwang-Jen and Choeh, Kyuchul and Yang, Yanling and Cao, Qixiang and Reichardt, Juergen KV and Niihira, Shizuhiro and Imamura, Takuji and Yamono, Tsunekazu (2001) A Genetic Factor for Age-Related Cataract: Identification and Characterization of a Novel Galactokinase Variant, "Osaka," in Asians. American Journal of Human Genetics, 68 (4). pp. 1036-1042.
DRUM DOI
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 GALKdeficiency. GALK activity and the amount of immunoreactive protein in the mutant were both 20% of normal construct in expression analysis. The Km values for galactose and ATP-Mg2+ 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%; ) in Japanese individuals with bilateral P ! .023 cataract. This variant probably originated in Japanese and Korean ancestors and is one of the genetic factors that causes cataract in elderly individuals.