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5′‐Insulin Gene VNTR Polymorphism Is Specific for Type 1 Diabetes
Author(s) -
PÉREZ DE NANCLARES GUIOMAR,
BILBAO J. RAMÓN,
CALVO BEGOÑA,
VITORIA JUAN CARLOS,
VÁZQUEZ FEDERICO,
CASTAÑO LUIS
Publication year - 2003
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1288.050
Subject(s) - type 1 diabetes , allele , autoantibody , genotype , locus (genetics) , genetics , medicine , population , disease , immunology , autoimmune disease , genetic predisposition , diabetes mellitus , gene , biology , endocrinology , antibody , environmental health
A bstract : The VNTR region located at the 5′‐end of the insulin gene on chromosome 11p15.5 is linked to susceptibility to type 1 diabetes mellitus (T1DM), and class I alleles have been associated with increased risk of disease, whereas class III alleles are considered to be protective. Although a potential effect on the expression level of thymic insulin and a consequent abnormal tolerance have been proposed as an explanation, it is still not clear whether the association is specific for T1DM or whether it is shared by other autoimmune disorders. To investigate the contribution of INS ‐VNTR to the genetic susceptibility to autoimmune disorders, we analyzed 102 autoantibody‐positive T1DM patients, 59 patients with celiac disease (CD), and 57 patients with Addison's disease (ADD), as well as 111 unrelated healthy individuals from the general population. When analyzing the results, class I allele frequencies were 85.8% in the T1DM group, 77% among CD patients, 71% in the ADD group, and 76.1% in the general population. Association with increased risk was seen only in the T1DM group ( pc = 0.015). Risk to T1DM was associated with the class I/class I homozygous genotype (RR, 1.92; 95% CI, 1.03‐3.6). In conclusion, INS ‐VNTR does not seem to be involved in the susceptibility to autoimmune diseases other than T1DM and can be considered a diabetes‐specific locus.