ECE2006 Poster Presentations Thyroid (174 abstracts)
University Hospital of Vigo, Vigo, Spain.
Introduction: Graves disease (GD) is inherited as a complex multigenic disorder. One of the most promising genes for susceptibility to GD is cytotoxic T lymphocyte antigen-4 (CTLA4), a negative regulator of T-cell activation.
Objective: The aim of this study was to determine whether A/G polymorphism in exon 1 of the CTLA-4 gen was associated with GD in spanish patients.
Patients and methods: Fifty one adult GD patients and 25 unrelated controls were analyzed. GD was defined as hyperthyroidism together with following criteria: diffuse goiter, thyroglobulin and/or thyroid peroxidase abs and/or ophthalmopathy. Polymorphism were analyzed using a restriction enzyme digestion with BbvI of polymerasa chain reaction (PCR) amplified genomic.
Results: Forty three women (84%) in the total of 51 patients studied. The medium age was 41,25 years (1875). The distribution of genotype frequencies and the frequencies of the A and G alleles differed between GD subjects and controls (see table). In the control group we have not detected homozygous for the G allele.
A49G Mutation | Graves | Controls | P |
Genotype Distribution | |||
A/A | 21 (41) | 24 (58) | ns |
A/G | 18 (35) | 21 (42) | ns |
G/G | 12 (24) | 0 | 0.005 |
Alleles Frequency | |||
A | 30 (59) | 41 (82) | 0.01 |
G | 21 (41) | 11 (22) | 0.04 |
Conclusions: Our data show that G-carrying genotypes of polymorphism CTLA4 A/G are associated with increase in risk of GD in our region. The G allele and the GG genotype were increased among Spanish patients. We not found association between AG genotype and GD like other previous studies in Caucasian patients. CTLA-4 polymorphism varies according to ethnic group and environmental variables and it is important its identification than in future can influence the selection of treatment of GD.