- SNP in the intron (noncoding region) of the thyroid stimulating hormone receptor gene [R].
- More likely to occur (LD) with a SNP in the coding region of TSHR that changes the TSHR protein
- TT Allele = Decrease in presence of full TSHR in favor of a split version of the protein (called ST5) that increases its ability to bind to the antibody, thus increasing the production of thyroid hormone and the growth of thyroid cells [R].
- CT Allele = Increased ratio of full length TSHR to ST5 [R]
- CC Allele = Even more full length TSHR relative to the mutated version ST5 [R].
The Minor allele "T" is associated with:
- TT= Increased susceptibility to Graves’ disease (in European and Chinese Cohorts) [R1, R2, R3].
- Increased risk of developing Graves orbitopathy in young Grave's disease patients (T or TT) [R].
- Increased thyroid hormone production (hyperthyroidism) [R].
- Symptoms include weight loss, fatigue, muscle weakness, decreased tolerance to heat, increased heart rate, nervousness or irritability, trouble sleeping, and a goiter [R].
The Major allele "C" is associated with:
Production of the full TSHR protein, allowing for normal production of thyroid hormone and normal growth of thyroid cells [R].