Investigation of a male patient with low serum TSH and TT4, but raised FT4 concentrations and thyroid stimulating immunoglobulins, identified hemizygosity for a pathogenic mutation in the TBG (SERPINA7) gene, hence signifying coincident TBG deficiency and Graves disease (72). This evidence concerns the gene SERPINA7 and hyperinsulinemic hypoglycemia, familial, 4.