Graves' disease in Brazilian children and adults: lack of genetic association with CTLA-4 +49A>G polymorphism.
OBJECTIVE
In several populations, major histocompatibility complex and CTLA-4 (cytotoxic T lymphocyte antigen-4) gene polymorphisms are related to adult subjects with Graves' disease (GD). Our aim was to study the association of +49A>G polymorphism of the CTLA-4 gene in Brazilian children and adults with GD and its correlation with clinical and laboratory markers of disease severity.


METHODS
CTLA-4 +49A>G polymorphism was established by polymerase chain reaction-restriction fragment length polymorphism analysis in 44 children and 72 adults with GD and compared to a stringent control group consisting of octogenarians with no history of thyroid disease; free T4 and T3 levels and T3/T4 ratio, antithyroid antibodies, and Graves' ophthalmopathy were also evaluated according to genotype.


RESULTS
No significant difference was found in the frequency of CTLA-4 +49A>G polymorphism among children and adults with GD compared to controls and within groups. There was no significant correlation between the presence of G allele and Graves' ophthalmopathy, gender, age at diagnosis, and biochemical markers of disease severity.


CONCLUSIONS
The frequency of CTLA-4 +49A>G polymorphism is not different in children and adults with GD compared to the normal control population and does not seem to contribute independently to the severity of the clinical presentation of GD.
Namo Cury
Adriano
A
Endocrine and Metabolic Unit, Santa Casa de São Paulo, São Paulo, Brazil. anamo_cury@hotmail.com
Longui
Carlos Alberto
CA
Kochi
Cristiane
C
Calliari
Luiz Eduardo
LE
Scalissi
Nilza
N
Salles
João Eduardo
JE
Neves Rocha
Mylene
M
Barbosa de Melo
Mônica
M
Rezende Melo
Murilo
M
Monte
Osmar
O
D000328:Adult; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001938:Brazil; D060908:CTLA-4 Antigen; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D006111:Graves Disease / Q000097:blood / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D013974:Thyroxine / Q000097:blood / Q000276:immunology; D014284:Triiodothyronine / Q000097:blood / Q000276:immunology
D015703:Antigens, CD; D001323:Autoantibodies; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D014284:Triiodothyronine; D013974:Thyroxine