Hypercholesterolemia in Two Siblings with Resistance to Thyroid Hormones Due to Disease-Causing Variant in Thyroid Hormone Receptor (<i>THRB</i>) Gene
Maja Pajek,
Magdalena Avbelj Stefanija,
Katarina Trebusak Podkrajsek,
Jasna Suput Omladic,
Mojca Zerjav Tansek,
Tadej Battelino,
Urh Groselj
Affiliations
Maja Pajek
Department of Paediatric Surgery and Intensive Care, University Medical Centre Ljubljana, Bohoričeva 20, 1000 Ljubljana, Slovenia
Magdalena Avbelj Stefanija
Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Bohoričeva 20, 1000 Ljubljana, Slovenia
Katarina Trebusak Podkrajsek
Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Bohoričeva 20, 1000 Ljubljana, Slovenia
Jasna Suput Omladic
Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Bohoričeva 20, 1000 Ljubljana, Slovenia
Mojca Zerjav Tansek
Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Bohoričeva 20, 1000 Ljubljana, Slovenia
Tadej Battelino
Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Bohoričeva 20, 1000 Ljubljana, Slovenia
Urh Groselj
Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Bohoričeva 20, 1000 Ljubljana, Slovenia
Resistance to thyroid hormone beta (RTHβ) is a syndrome characterized by a reduced response of target tissues to thyroid hormones. In 85% of cases, a pathogenic mutation in the thyroid hormone receptor beta (THRB) gene is found. The clinical picture of RTHβ is very diverse; the most common findings are goiter and tachycardia, but the patients might be clinically euthyroid. The laboratory findings are almost pathognomonic with elevated free thyroxin (fT4) levels and high or normal thyrotropin (TSH) levels; free triiodothyronin (fT3) levels may also be elevated. We present three siblings with THRB mutation (heterozygous disease-variant c.727C>T, p.Arg243Trp); two of them also had hypercholesterolemia, while all three had several other clinical characteristics of RTHβ. This is the first description of the known Slovenian cases with RTHβ due to the pathogenic mutation in the THRB gene. Hypercholesterolemia might be etiologically related with RTHβ, since the severity of hormonal resistance varies among different tissues and hypercholesterolemia in patients with THRB variants might indicate the relatively hypothyroid state of the liver. We suggest that cholesterol levels are measured in all RTHβ patients.