Abstract

TG gene mutations have been identified in some people who have a goiter but normal or boarder line thyroglobulin levels. These mutations are either caused by gene deletion or single nucleotide mutation as a result. This study aim to screen the frequency of g.IVS5+1G to A mutation of TG gene and thyroid hormone levels among Iraqi thyroid disorders. g.IVS5+1G to A mutation of TG gene and thyroid hormones levels were detected in Iraqi thyroid disorders including 16 metastatic follicular thyroid carcinoma, 31 toxic goiter, 32 non toxic goiter and 19 hypothyroidism in addition to 25 normal control. The g.IVS5+1G to A mutation of TG gene screened by LAN-PCR. The heterozygous point mutation g.IVS5+1G  to A was detected at position +1 of the splice donor site of intron 5 in 57% of cancer patients, 55% of toxic goiter and in 44% non toxic goiter patients but not in patients with hypothyroidism. The results also showed no correlation between hormones levels and detected mutation. We conclude that the g IVS5+1G>A mutation which caused fusion  of  exons 4 and 6 was detected in high frequency in Iraqi patients with thyroid disorders and no correlation was found between mutation and the levels of the thyroid hormones.

Key words: TG gene, thyroid cancer, mutation, goiter.