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Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review

Familial dysalbuminemic hyperthyroxinemia (FDH) is the most common cause of the inherited increase of serum thyroxine in Caucasians. This disorder occurs due to a missense mutation in the human serum albumin, resulting in an increased affinity of thyroxine to the binding sites on the human serum alb...

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Autores principales: Mahendhar, Rupak, Shahbaz, Amir, Riaz, Maria, Aninyei, Michael, Reich, David M, Sachmechi, Issac
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cureus 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6126704/
https://www.ncbi.nlm.nih.gov/pubmed/30197844
http://dx.doi.org/10.7759/cureus.2903
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author Mahendhar, Rupak
Shahbaz, Amir
Riaz, Maria
Aninyei, Michael
Reich, David M
Sachmechi, Issac
author_facet Mahendhar, Rupak
Shahbaz, Amir
Riaz, Maria
Aninyei, Michael
Reich, David M
Sachmechi, Issac
author_sort Mahendhar, Rupak
collection PubMed
description Familial dysalbuminemic hyperthyroxinemia (FDH) is the most common cause of the inherited increase of serum thyroxine in Caucasians. This disorder occurs due to a missense mutation in the human serum albumin, resulting in an increased affinity of thyroxine to the binding sites on the human serum albumin (HSA) molecule. HSA is a carrier protein of thyroid hormones and only 10% of thyroxine (T4) is bound to human serum albumin, 75% is bound to thyroxine-binding globulin, 15% to transthyretin, and 0.03% is free. The disorder is characterized by a greater elevation of serum thyroxine than triiodothyronine (T3). The high serum concentration of T4 is due to the modification of a binding site located in the N-terminal half of HSA (in subdomain IIA). Arg218 or Arg222 gets replaced with smaller amino acids, such as histidine, proline, or serine, due to missense mutation; this reduces the steric hindrances in the binding site and creates a high-affinity binding site for thyroxine. We herein report a case of FDH with a characteristically elevated total T4 and normal free T4 (measured by equilibrium dialysis).
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spelling pubmed-61267042018-09-07 Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review Mahendhar, Rupak Shahbaz, Amir Riaz, Maria Aninyei, Michael Reich, David M Sachmechi, Issac Cureus Endocrinology/Diabetes/Metabolism Familial dysalbuminemic hyperthyroxinemia (FDH) is the most common cause of the inherited increase of serum thyroxine in Caucasians. This disorder occurs due to a missense mutation in the human serum albumin, resulting in an increased affinity of thyroxine to the binding sites on the human serum albumin (HSA) molecule. HSA is a carrier protein of thyroid hormones and only 10% of thyroxine (T4) is bound to human serum albumin, 75% is bound to thyroxine-binding globulin, 15% to transthyretin, and 0.03% is free. The disorder is characterized by a greater elevation of serum thyroxine than triiodothyronine (T3). The high serum concentration of T4 is due to the modification of a binding site located in the N-terminal half of HSA (in subdomain IIA). Arg218 or Arg222 gets replaced with smaller amino acids, such as histidine, proline, or serine, due to missense mutation; this reduces the steric hindrances in the binding site and creates a high-affinity binding site for thyroxine. We herein report a case of FDH with a characteristically elevated total T4 and normal free T4 (measured by equilibrium dialysis). Cureus 2018-07-01 /pmc/articles/PMC6126704/ /pubmed/30197844 http://dx.doi.org/10.7759/cureus.2903 Text en Copyright © 2018, Mahendhar et al. http://creativecommons.org/licenses/by/3.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Endocrinology/Diabetes/Metabolism
Mahendhar, Rupak
Shahbaz, Amir
Riaz, Maria
Aninyei, Michael
Reich, David M
Sachmechi, Issac
Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review
title Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review
title_full Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review
title_fullStr Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review
title_full_unstemmed Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review
title_short Effect of Albumin Polymorphism on Thyroid Hormones: A Case Report and Literature Review
title_sort effect of albumin polymorphism on thyroid hormones: a case report and literature review
topic Endocrinology/Diabetes/Metabolism
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6126704/
https://www.ncbi.nlm.nih.gov/pubmed/30197844
http://dx.doi.org/10.7759/cureus.2903
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