title: Relationship of large multifunctional proteasome 7 gene polymorphism with susceptibility to type 1 diabetes mellitus and DR3 gene.
abstract: OBJECTIVE
  To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.
  
  
  METHODS
  LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A < or = 14 years, group B 15-30 years, group C > or = 31 years.
  
  
  RESULTS
  In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P < 0.05) and that of LMP7-B/A was higher (54% vs 31%, P < 0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P < 0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset.
  
  
  CONCLUSIONS
  LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.
authors.affiliation: Department of Endocrinology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University of Medical Sciences, Guangzhou 510120, China.
authors.forename: H
authors.initials: H
authors.lastname: Ding
authors.forename: H
authors.initials: H
authors.lastname: Cheng
authors.forename: Z
authors.initials: Z
authors.lastname: Fu
authors.forename: L
authors.initials: L
authors.lastname: Yan
authors.forename: G
authors.initials: G
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D003546:Cysteine Endopeptidases; D004247:DNA / Q000235:genetics; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D015803:HLA-DR3 Antigen / Q000235:genetics*; D006801:Humans; D008297:Male; D009097:Multienzyme Complexes; D011110:Polymorphism, Genetic; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000235:genetics*
chemical_list: D015803:HLA-DR3 Antigen; D009097:Multienzyme Complexes; D011506:Proteins; D004247:DNA; D003546:Cysteine Endopeptidases; C077436:LMP7 protein; D046988:Proteasome Endopeptidase Complex