[Screening of rare blood group Lu(a-b-) phenotype and study of its molecular basis in ethnic Han Chinese from Shanghai region].

Objective To study the frequency of rare blood group Lu （a- b--） phenotype in a population from Shanghai region, and to explore the molecular basis of Lu（a--b--） by detecting the Lu and Lu relative mediator gene EKLF/KLF1. Methods Donors from Shanghai region were screened for Lutheran blood group by monoclonal anti-Lub using serological methods. Individuals with Lu（b--） were determined Lua, P1 and i antigens. Fifteen exons of the LU gene and 3 exons of the EKLF/KLF1 gene for the identified Lu（a--b--） samples were amplified and sequenced. Results Ten Lu（a--b--） donors were obtained from 44 331 donors from Shanghai region. No homozygous or heterozygous mutations were found in the LU gene, whilst 7 mutations in EKLF/KLF1 gene were identified in the 10 samples. Conclusion The frequency of rare Lu（a--b--） blood group in Shanghai was approximately 0.02 %, and all the individuals had an In（Lu） phenotype. The molecular basis of such samples may be related to mutations in the EKLF/KLF1 gene. Key words: Rare blood type;  Lutheran blood type;  LU gene;  EKLF/KLF1 gene