|(C;C)||1.5||Hypothyroid patients might benefit from combination T4/T3 therapy (?)|
|(C;T)||1.5||Hypothyroid patients might benefit from combination T4/T3 therapy (?)|
rs225014, also known as Thr92Ala, represents a variant in the deiodinase, iodothyronine, type II DIO2 gene on chromosome 14. In dbSNP orientation for this SNP, the more common (T) allele encodes the Thr (threonine) and the somewhat less common (C) allele encodes the Ala (alanine) at this position in the DIO2 protein.
Hypothyroidism is commonly treated by thyroid replacement therapy consisting of levothyroxine, which usually results in normal levels of serum free T4 (FT4), T3 and TSH. Patients who don't show much improvement may have lower brain thyroid levels (not reflected in their serum levels) correlated to the number of rs225014(C) alleles they carry, and these patients may benefit from combined levothyroxine and liothyronine therapy, according to a 2009 study of 500 patients.[PMID 19190113].
The use of such combination therapy remains questionable according to the American Thyroid Association and the European Thyroid Association, as both organizations have stated that multiple studies of levothyroxine and liothyronine combination therapy for treating hypothyroidism have not so far led to a clear conclusion about its benefits over levothyroxine monotherapy.[PMID 26544166],[PMID 24782999]
[PMID 19427350] Association of genetic polymorphisms in the type II deiodinase gene with bipolar disorder in a subset of Chinese population
[PMID 20178852] Association Study between Polymorphisms in Selenoprotein Genes and Susceptibility to Kashin-Beck Disease
[PMID 19352319] Novel insights into thyroid hormones from the study of common genetic variation.
[PMID 19190113] Common variation in the DIO2 gene predicts baseline psychological well-being and response to combination thyroxine plus triiodothyronine therapy in hypothyroid patients.
[PMID 23974776] Combination L-T3 and L-T4 therapy for hypothyroidism.
[PMID 18334578] Identification of DIO2 as a new susceptibility locus for symptomatic osteoarthritis.
[PMID 20566590] Association of the type 2 deiodinase Thr92Ala polymorphism with type 2 diabetes: case-control study and meta-analysis
[PMID 21715540] The Type 2 Deiodinase ORFa-Gly3Asp Polymorphism (rs12885300) Influences the Set Point of the Hypothalamus-Pituitary-Thyroid Axis in Patients Treated for Differentiated Thyroid Carcinoma
[PMID 22492780] Increased type II deiodinase protein in OA-affected cartilage and allelic imbalance of OA risk polymorphism rs225014 at DIO2 in human OA joint tissues.
[PMID 15286152] Positive association of the DIO2 (deiodinase type 2) gene with mental retardation in the iodine-deficient areas of China.
[PMID 18492748] A common variation in deiodinase 1 gene DIO1 is associated with the relative levels of free thyroxine and triiodothyronine.
[PMID 18815314] Cellular and molecular basis of deiodinase-regulated thyroid hormone signaling.
[PMID 20930717] D2 Thr92Ala and PPARgamma2 Pro12Ala polymorphisms interact in the modulation of insulin resistance in type 2 diabetic patients.
[PMID 21685153] Type 2 deiodinase and host responses of sepsis and acute lung injury.
[PMID 24058403] Association study of polymorphisms in selenoprotein genes and Kashin-Beck disease and serum selenium/iodine concentration in a Tibetan population
[PMID 26098717] Association of the DIO2 gene single nucleotide polymorphisms with recurrent depressive disorder.
|qualified_impact||Insufficiently evaluated not reviewed|