OBJECTIVETo investigate two polymorphism sites of exon 4 in T cells, immunoglobulin domain and mucin domain protein-1 (TIM-1, also human hepatitis A virus cellular receptor-1) and to detect whether they are associated with allergic asthma in children of the Hans in Hubei province of China.

METHODSThe ins/del and IVS 8+9 G/A polymorphisms in TIM-1 were detected with polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The genotypes and alleles frequencies were calculated and analyzed.

RESULTS(1) Two alleles, a wide type del and a variant allele ins were identified in the TIM-1 exon 4. The genotype frequencies of ins/ins, ins/del, and del/del were 0.065,0.326, and 0.608 respectively in the healthy population of the Hans. Another IVS 8/9 G/A polymorphism was also found. The genotype frequencies of A/A, G/A, G/G were 0.022, 0.196 and 0.783, respectively. (2) The genotype frequencies of ins/ins, ins/del, and del/del were 0.045, 0.318, and 0.636 respectively in the allergic asthma population in children of the Hans. No significant difference in ins/del polymorphism was found between allergic asthma patients and control subjects. Another 8/9 IVS G/A polymorphism was also found. The genotype frequencies of A/A, G/A and G/G were 0.009, 0.209 and 0.782 respectively in allergic asthma. No significant difference in IVS G/A polymorphism was found between allergic asthma patients and control subjects.

CONCLUSIONThe genotype and allele frequencies in the two polymorphism sites in TIM-1 in healthy population of the Hans from Hubei province of China were similar to those in Japanese. The two polymorphism sites of TIM-1 are not associated with allergic asthma in Chinese children.