title: Incidence rate of type 1 diabetes in Santiago (Chile) by HLA-DQA1 and DQB1 genotypes.
abstract: The aim of this study was to estimate annual incidence rate of type 1 diabetes according to the levels of genetic susceptibility provided by HLA-DQA1 and HLA-DQB1 genotypes. Two information sources were used: (1) a population-based incidence study in which 61 incident cases were ascertained during 1 year in Santiago, Chile (incidence rate: 4.11 cases per 100,000 children per year) and (2) a case-control comparison of 57 cases (recruited from the incidence study) and 125 controls. Susceptibility alleles were defined as DQA1*0301 and DQA1*0501 for DQA1 gene and alleles DQB1*0201 and DQB1*0302 for DQB1 gene. In DQA1 gene, the highest point estimate of the incidence rate was calculated for the genotype DQA1*0501/DQA1*0501 (33.04 cases per 100,000 children aged less than 15 years old and per year; 95% CI: 9.22-118.33). In the DQB1 gene, the highest risk was estimated for the genotype DQB1*0201/DQB1*0201 (20.35 cases per 100,000 children aged less than 15 years old and per year; 95% CI: 5.26-78.67). This study shows an application on how a transformation of the logistic equation based on Bayes' theorem can be used to estimate incidence rates from case-control studies and population-based incidence rates.
authors.affiliation: Genetics and Metabolic Diseases Program, Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
authors.forename: N
authors.initials: N
authors.lastname: Díaz
authors.forename: M A
authors.initials: MA
authors.lastname: Méndez
authors.forename: F
authors.initials: F
authors.lastname: Pérez-Bravo
authors.forename: E
authors.initials: E
authors.lastname: Carrasco
authors.forename: J L
authors.initials: JL
authors.lastname: Santos
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002677:Chile / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D011237:Predictive Value of Tests; D012042:Registries
chemical_list: D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen