ALB and hyperthyroxinemia: This dominantly inherited condition, due to heterozygous variants (Arg218His, Arg218Ser, Arg218Pro, Arg222Ile) in circulating albumin which alter its binding affinity for TH, causes artefactual elevation of FT4 and FT3 measurements with nonsuppressed TSH levels in euthyroid individuals, raising the possibility of Familial Dysalbuminemic Hyperthyroxinemia (FDH) being misdiagnosed as RTHβ or a TSH-secreting pituitary tumor.