Genetic polymorphisms of TIM-3 and its association with asthma in familial cluster asthma.

INTRODUCTION: TIM-3 gene polymorphisms strongly influence familial asthma susceptibility. AIM: This study investigates the genetic association of polymorphisms at rs9313441, rs511898, and rs953569 loci in the T cell immunoglobulin and mucin domain protein 3 (TIM-3) with familial asthma aggregation. MATERIAL AND METHODS: Thirty asthma patients admitted to our hospital, diagnosed between December 2021 and December 2022, served as probands. We analysed three generations of direct blood relatives, dividing them into three groups (Generation I, II, III), each comprising 30 individuals. Data collected included demographic and high-risk asthma factors like gender, age, ethnicity, body mass index, and histories of asthma, allergies, and smoking. We compared these non-genetic factors across groups and conducted unilateral direct sequencing to determine allele and genotype frequencies at key loci. RESULTS: The rs511898 locus showed no significant difference in the CC/CT genotype and allele distribution among the groups; however, the TT genotype was significantly more frequent in Generations I and II compared to Generation III (p < 0.05). At the rs953569 locus, the AA genotype was significantly more prevalent in Generation III than in the other groups (p < 0.05). The rs9313441 locus revealed a significantly higher frequency of the AG genotype in Generation III compared to the other two groups (p < 0.05), with no significant differences in GG and AA genotypes. CONCLUSIONS: There are distinct differences in TIM-3 gene expression across familial lines of asthma patients, and specific genotypes correlate with increased genetic susceptibility to asthma. Direct sequencing of these susceptibility genes aids in early identification and provides a foundation for targeted diagnosis, treatment, and preventive measures in familial asthma.