First Report of Familial Dysalbuminemic Hyperthyroxinemia With an ALB Variant.
Familial dysalbuminemic hyperthyroxinemia (FDH) is an inherited disease characterized by increased circulating total thyroxine (T4) levels and normal physiological thyroid function. Heterozygous albumin gene (ALB) variants have been reported to be the underlying cause of FDH. To our knowledge, there have been no confirmed FDH cases in Korea. We recently observed a female patient with mild T4 elevation (1.2 to 1.4-fold) and variable levels of free T4 according to different assay methods. Upon Sanger sequencing of her ALB, a heterozygous c.725G>A (p.Arg242His) variant was identified. The patient's father and eldest son had similar thyroid function test results and were confirmed to have the same variant. Although the prevalence of FDH might be very low in the Korean population, clinical suspicion is important to avoid unnecessary evaluation and treatment.
Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Division of Endocrinology and Metabolism, Department of Medicine, Gyeongsang National University School of Medicine, Jinju, Korea.
Yoon Young
YY
Cho
Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Ju Sun
JS
Song
Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Hyung Doo
HD
Park
Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Young Nam
YN
Kim
Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Hye In
HI
Kim
Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Tae Hyuk
TH
Kim
Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Jae Hoon
JH
Chung
Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. changski@skku.edu.
Chang Seok
CS
Ki
Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. swkimmd@skku.edu.
Sun Wook
SW
Kim
D000328:Adult; D000418:Albumins / Q000235:genetics*; D001483:Base Sequence; D005260:Female; D006579:Heterozygote; D006801:Humans; D050010:Hyperthyroxinemia, Familial Dysalbuminemic / Q000235:genetics*; D010375:Pedigree; D011863:Radioimmunoassay; D017422:Sequence Analysis, DNA; D013974:Thyroxine / Q000032:analysis
D000418:Albumins; D013974:Thyroxine
Abnormal thyroid function test; Albumin gene; Familial dysalbuminemic hyperthyroxinemia; Variant