title: High incidence of complement C9 deficiency in Koreans.
abstract: Complement 9 deficiency is the most common complement deficiency in Japan, but it is rare in western countries. Because of Korea's geographical proximity to Japan, C9 deficiency in Korea has also been assumed to be common although this has never before been proven. We investigated complement deficiency in the serum samples of 6,159 Korean hospital outpatients. The deficiency was screened by a sensitive hemolytic assay and was confirmed by immunoassay of each complement component. Three C9-deficient individuals were found, giving an incidence of 0.049%, which is lower than that in Japan but still a considerable figure. Complement deficiencies other than that of C9 were not detected in this study. It is therefore necessary to consider the possibility of C9 deficiency in the interpretation of unexpectedly low complement-mediated hemolytic activity in East Asians.
authors.affiliation: Department of Laboratory Medicine, Hallym University College of Medicine, Anyang, Korea. kangheejung@hallym.or.kr
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Kang
authors.forename: Han Sung
authors.initials: HS
authors.lastname: Kim
authors.forename: Yung Kyoung
authors.initials: YK
authors.lastname: Lee
authors.forename: Hyoun Chan
authors.initials: HC
authors.lastname: Cho
mesh_terms: D044466:Asian People; D003186:Complement C9 / Q000172:deficiency*; D006801:Humans; D015994:Incidence; D007723:Korea / Q000453:epidemiology; D010045:Outpatients
chemical_list: D003186:Complement C9