Premium
Detection of Hp del among Thais, a deleted allele of the haptoglobin gene that causes congenital haptoglobin deficiency
Author(s) -
Shimada Eiko,
Odagiri Miki,
Chaiwong Kriangsak,
Watanabe Yoshihisa,
Anazawa Masako,
Mazda Toshio,
Okazaki Hitoshi,
Juji Takeo,
O'Charoen Rachanee,
Tadokoro Kenji
Publication year - 2007
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.2007.01473.x
Subject(s) - haptoglobin , thais , allele , immunology , biology , allele frequency , microbiology and biotechnology , medicine , gene , genetics , demography , sociology
BACKGROUND: Congenital haptoglobin deficiency is a risk factor for anaphylactic nonhemolytic transfusion reactions in Japan. The deleted allele of the haptoglobin gene, Hp del , which causes congenital haptoglobin deficiency, has also been observed in other Northeast Asian populations, such as Korean and Chinese persons. It has not been reported in several African and European‐African populations, however, or investigated in other countries. STUDY DESIGN AND METHODS: To investigate the distribution of congenital haptoglobin deficiency in Southeast Asian countries, blood samples collected from 200 randomly selected healthy Thai volunteers were analyzed for serum haptoglobin and the haptoglobin gene. Plasma haptoglobin concentration was measured to identify haptoglobin deficiency. Haptoglobin phenotyping was performed with sodium dodecyl sulfate–polyacrylamide gel electrophoresis followed by Western blotting. The presence of the Hp del allele was determined with genomic DNA by an Hp del ‐specific polymerase chain reaction (PCR) method. RESULTS: There were no haptoglobin‐deficient subjects detected among the 200 Thais. Their haptoglobin phenotypes were as follows: Hp 1‐1 in 10, Hp 2‐1 in 81, and Hp 2‐2 in 109. Six individuals heterozygous for Hp del were detected. The frequency of the Hp del allele was calculated to be 0.015. The prevalence of haptoglobin deficiency caused by Hp del homozygosity was estimated to be approximately 1 in 4000. CONCLUSION: Congenital haptoglobin deficiency caused by Hp del homozygosity is presumed to be present in Thailand as a risk factor for anaphylactic transfusion reactions with a frequency similar to that in Japan. The causative deleted allele of the haptoglobin gene, Hp del , is distributed among Southeast Asian populations as well as among Northeast Asian populations.