Clinical and genetic heterogeneity in Mexican patients with ulcerative colitis.

Ulcerative colitis (UC) is an inflammatory bowel disease of unknown etiology. Genetic factors implied on its onset and severity may include genes located within the class II major histocompatibility complex (MHC) region. The aim of this study was to determine the relationship between human leukocyte antigen (HLA)-DRB1 alleles with the clinical disease patterns of UC in Mexican Mestizo patients.

HLA-DR antigen frequencies in Mexican patients with dengue virus infection: HLA-DR4 as a possible genetic resistance factor for dengue hemorrhagic fever.

The human leukocyte antigen DRB1 locus (HLA-DRB1) was typed in genomic DNA extracted from whole blood samples of 34 Mexican dengue hemorrhagic fever (DHF) patients and 47 dengue fever (DF) patients, by polymerase chain reaction-sequence-specific oligonucleotide reverse dot blot. HLA-DRB1*04 was negatively associated with risk of DHF (OR 0.31, 95% CI 0.