Detection of IL-4 proximal promoter mutation of asthmatic patients and preliminary analysis

Zhou YF, Li CR, Wu JM, Lam Wk

1 Shenzhen Children’s Hospital, Shenzhen, China

2 Molecular Biological Laboratory of Union Hospital of Tongji Medical University

3 Department of Chemical Pathology, Chinese University of Hong Kong, Hong Kong

 

Objective: To clone and detect mutation sites within interleukin-4 (IL-4) promoter of asthmatic patients.

Methods: The IL-4 proximal promoter segments were obtained by Polymerase chain reaction (PCR) with genomic DNA as template .Four patients’ samples were selected from thirty asthmatic patients and twenty healthy children through PCR and single strand conformation polymorphysimPCR-SSCP. The PCR segments of the four patients were cloned into plasmids JX2. The PCR inserts were sequenced by dideoxy chain termination method in the end.

Results: The IL-4 proximal promoter sequences of the normal child were the same as the sequences of the gene pool. Some new potential important sites were found: (1) A C to A transversion located at -229 position was just within PRE-I element in one patient. (2) A C to T transition adjacent to NRE-II elements and an extra G adjacent to TATA box were found in two patients. (3) A five bases nucleotide deletion was found near STAT-6 RE element in one patient.

Conclusion: Multiple allelic forms of the human IL-4 promoter do exist within asthmatic patients. These polymorphism sites might result in aberrant expression of IL-4 gene.

 
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