CHARACTERIZATION OF POLYMORPHISMS OF AN INTERLEUKIN-1 RECEPTOR-TYPE-1GENE (IL1RI) PROMOTOR REGION (P2) AND THEIR RELATION TO INSULIN-DEPENDENT DIABETES-MELLITUS (IDDM)

We have identified two PstI polymorphisms of the interleukin 1 recepto r type I gene (IL1RI). One of these (RFLP-A) showed significant associ ation to IDDM (P = 0.027), whereas no difference between patients and control subjects was found for RFLP-B (p = 0.42). RFLP-A was physicall y mapped to the 5'UTR of the gene. We sequenced and analysed a 411 bp region of a putative promotor region (P2) around RFLP-A. RFLP-A was du e to a C to T transition in exon 1B of the IL1RI gene. This single-bas e mutation did not affect any known transcription factor recognition s equence or the predicted secondary mRNA structure, In addition, we fou nd two other single-base substitutions in more than one individual. Ne ither of these showed specific disease association or absolute linkage with the RFLP-A. (C) 1995 Academic Press Limited.