[Biological differences on onset among type 1A diabetics in relation to HLA-DQ genetic markers].

Background And Objective: The hypothesis that diabetes mellitus presentation partially depends on the genetic characteristics of the patient has been proposed. Up to date this kind of studies have been made by serology, so there are no data about the role played by DQ haplotypes in the presentation and clinical importance of DM1. This fact is analysed in the present study.

Patients And Method: We studied DQ haplotypes (molecular biology) in 86 patients affected by DM1. Their relationship with several parameters found on illness debut, such as age, sex, C peptid and clinical importance are analysed.

Results: 89% of the patients showed a DQ that increases the risk of diabetes. Average age on onset was 16 years and the median age 9 years. No differences in relation to sex were observed. DQA1*0501, 0301/DQB1*0201, 0302 heterocygotes show an earlier onset (9 years, opposite to 17 in the rest) and the youngest (smaller than 16 years) they have to the onset a smaller pancreatic reservation (peptid C of 0.37 ng/dl in front of 1.4 of those bigger than this age).

Conclusions: DQA1*0501, 0301/DQB1*0201 heterocygocity increases the probability of an earlier and more aggressive debut of the illness, being related this characteristic younger debut to a smaller pancreatic reservation.