Transient hypocalcemia was seen in patients who underwent a total thyroidectomy because of papillary thyroid carcinoma (n = 3; all three patients underwent a lymph node dissection), Graves’ disease (n = 4), goiter due to a congenital activating TSH receptor mutation (n = 1), goiter due to Pendred syndrome (n = 1) and a prophylactic thyroidectomy (n = 1). This evidence concerns the gene TSHR and Graves disease.