title: [Early infancy onset of type 1A diabetes mellitus in dizygotic twins: association with genetic and environmental factors].
abstract: The onset of type 1A diabetes before the first year of age is a rare condition and is probably due to an interaction between genetic and environmental factors (infection), which, together, may explain such an early event. Studies say that about 15% of newly diagnosed type 1 diabetic patients had human Cytomegalovirus (CMV) specific viral genome in their lymphocytes. We report two cases of dizygotic twins with type 1 diabetes onset in their first 9 months of age, with genetic homogeneity (for HLA DR3/DR4 alleles), a history of CMV infection (positive IgG and urinary PCR) and positive antibody anti-GAD (9.6 UI/ml), present only in the second twin. Although they were dizygotic twins, which concordance rate is 3.8%, they assume the equivalent risk as monozygotic (40%) as they have similar high risk genotype (HLA) for type 1 diabetes. We believe that both time concordance and also the early onset of diabetes are due to an association between infection and the high genetic liability.
authors: Departamento de Diabetes, Serviço de Endocrinologia e Metabologia, Faculdade de Ciências Médicas, Hospital Universitário Pedro Ernesto, Universidade do Estado do Rio de Janeiro.
authors: Lucianne R M
authors: LR
authors: Tannus
authors: Dhiãnah S
authors: DS
authors: Oliveira
authors: Alessandra S M
authors: AS
authors: Matheus
authors: Edna F
authors: EF
authors: Cunha
authors: Marília B
authors: MB
authors: Gomes
mesh_terms: D003587:Cytomegalovirus / Q000235:genetics*; D003586:Cytomegalovirus Infections / Q000150:complications*; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000821:virology; D004200:Diseases in Twins / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006681:HLA-D Antigens / Q000235:genetics; D006801:Humans; D007223:Infant; D008297:Male; D014429:Twins, Dizygotic / Q000235:genetics*
chemical_list: D006681:HLA-D Antigens