title: Familial Dysalbuminemic Hyperthyroxinemia in a Japanese Man Caused by a Point Albumin Gene Mutation (R218P).
abstract: Familial dysalbuminemic hyperthyroxinemia (FDH) is a familial autosomal dominant disease caused by mutation in the albumin gene that produces a condition of euthyroid hyperthyroxinemia. In patients with FDH, serum-free thyroxine (FT4) and free triiodothyronine (FT3) concentrations as measured by several commercial methods are often falsely increased with normal thyrotropin (TSH). Therefore, several diagnostic steps are needed to differentiate TSH-secreting tumor or generalized resistance to thyroid hormone from FDH. We herein report a case of a Japanese man born in Aomori prefecture, with FDH caused by a mutant albumin gene (R218P). We found that a large number of FDH patients reported in Japan to date might have been born in Aomori prefecture and have shown the R218P mutation. In conclusion, FDH needs to be considered among the differential diagnoses in Japanese patients born in Aomori prefecture and showing normal TSH levels and elevated FT4 levels.
authors.affiliation: Department of Endocrinology and Metabolism, Suifu Hospital, Mito, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Osaki
authors.affiliation: Department of Endocrinology and Metabolism, Division of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Sendai Thyroid Clinic, Sendai, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: Healthy Medical Center, Tohoku Kosai Hospital, Sendai, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University, Graduate School of Medicine, Sendai, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ozaki
authors.affiliation: Department of Endocrinology and Metabolism, Suifu Hospital, Mito, Japan; Division of Health Care Center, Mito Clinical Education and Training Center, Mito Kyodo General Hospital, Mito, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukazawa
keywords: FDH; albumin gene mutation (R218P); familial dysalbuminemic hyperthyroxinemia; resistance to thyroid hormone (RTH); syndrome of inappropriate secretion of TSH (SITSH)