Predisposition to idiopathic thrombocytopenic purpura maps close to the major  histocompatibility complex class I chain-related gene A.
Idiopathic thrombocytopenic purpura (ITP) is an autoimmune condition with poorly known etiology, characterized by platelet destruction. Genetic association studies of this disease are scarce, discrepant, and restricted to major histocompatibility complex (MHC) polymorphisms. Hence, a case-control study was conducted with an aim to map the MHC to IPT susceptibility using HLA-B and nine microsatellite loci encompassing MHC class I, II, and III regions. We compared the allelic frequencies in samples of unrelated healthy controls and ITP patients. After correction for multiple tests, only allele MICA*183, also known as A5.1, demonstrated an association, resulting in the identification of a major predisposing region close to STR-MICA. This result may highlight the putative functional role of MICA in the immune response to ITP.
Maia
Maria Helena Thomaz
MH
Laboratório de Genética Humana e Médica, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brasil. mariahtmaia@gmail.com
Peixoto
Raquel de Lima
Rde L
de Lima
Clayton Pereira Silva
CP
Magalhães
Milena
M
Sena
Leonardo
L
Costa
Perpétua do Socorro Silva
Pdo S
Barbosa
Fabíola Brasil
FB
de Oliveira
Layanna Freitas
LF
Romero
Matilde
M
Silva
Christina Nogueira de Araujo
CN
dos Santos
Eduardo José Melo
EJ
D000328:Adult; D001323:Autoantibodies; D001938:Brazil; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D015235:HLA-B Antigens / Q000235:genetics / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000276:immunology; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000276:immunology; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000235:genetics* / Q000276:immunology* / Q000503:physiopathology
D001323:Autoantibodies; D015235:HLA-B Antigens; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019038:Platelet Glycoprotein GPIb-IX Complex; C032193:glycoprotein receptor GPIb-IX