Insulin-like growth factor-I gene and insulin-like growth factor binding protein-3 polymorphism in patients with thyroid dysfunction.
OBJECTIVE
Thyroid hormones have important roles in normal growth and skeletal muscle development. IGF-I is one of the most important growth factors and is needed for the proliferation and development of thyroid cells. It stimulates fibroblasts, follicular and endothelia cells in thyroid gland. It has been shown that thyroid hormones play an important role in the regulation of IGF-I and IGFBP-3. In this study we proposed that IGF-I (CA)(19) and IGFBP-3-202 A/C gene polymorphism may affect thyroid functions. For this purpose, frequency of IGF-I (CA)(19) and IGFBP-3-202 A/C gene polymorphism in hypo- and hyperthyroid patients and possible role of these polymorphism in thyroid functions were investigated.


METHODS
This study was performed on 37 volunteer hyperthyroid and 76 hypothyroid patients as well as with 50 healthy subjects as controls. DNA isolation was applied in peripheral blood samples obtained from patients and controls. Required areas were amplified with PCR by using proper primers belonging to these gene areas from the isolated DNA samples. The products were evaluated with visualization by UV gel documentation system.


RESULTS
Frequency of IGF-I (CA)(19) gene polymorphism among hypothyroidism patients, hyperthyroidism patients and controls were statistically significant (chi(2) = 11.55, df = 4, p = 0.021). Genotypic variations between hyper- and hypothyroid patients were significant (chi(2) = 11.39, df = 2, p = 0.003), whereas there was no difference in IGF-I (CA)(19) gene polymorphism between the patients and controls. Differences in the IGFBP-3-202 A/C gene polymorphism between controls and hypo- as well as hyperthyroid patients were not significant. But IGFBP-3-202 A/C gene polymorphism genotype frequencies showed a significant difference between hypo- and hyperthyroid patients (chi(2) = 6.24, df = 2, p = 0.044).


CONCLUSIONS
These findings suggests that IGF-I (CA)(19) and IGFBP-3-202 A/C gene polymorphisms may be a risk factor for hypothyroidism.
Kursunluoglu
Raziye
R
Department of Physiology, University of Pamukkale, Denizli, Turkey. rkursunluoglu@pau.edu.tr
Turgut
Sebahat
S
Akin
Fulya
F
Bastemir
Mehmet
M
Kaptanoglu
Bünyamin
B
Genc
Osman
O
Turgut
Günfer
G
D001483:Base Sequence; D016022:Case-Control Studies; D017931:DNA Primers; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics*; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D013959:Thyroid Diseases / Q000235:genetics*
D017931:DNA Primers; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I