Abstract 10

Insulin-dependent diabetes mellitus (IDDM) is a chronic disorder that results from the autoimmune destruction of the insulin-producing pancreatic beta cells. Inherited susceptibility to IDDM is partially determined by HLA genes, being HLA-DQ A1 and B1 alleles considered among the most sensitive IDDM susceptibility markers in this context, transracial and familial analysis are efficient methods to identify haplotypes and alleles related to IDDM. OBJECTIVE: In this study, we analysed the distribution of the HLA class II alleles and haplotypes in 12 nuclear Chilean families with at least one child affected with IDDM. METHOD: The distribution of HLA class II alleles and haplotypes was examined by PCR/oligonucleotide probe typing. DNA extraction and amplification of the second exon of HLA DRB1, DQA1 and DQB1 loci were performed by means of standard techniques. RESULTS: Table 1 summarise the haplotype distribution in IDDM cases and their relatives free from the disease. CONCLUSION: Our data show that the presence of some haplotypes conformed by protective alleles (DR2, DR8, DQB1*0402 and DQB1*0602) or neutral alleles (DR1, DQB1*0501) are exclusively observed in the non diabetic population, and they would protect this group from the IDDM development.

Table 1 No caption available.
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