FHH1 and ADH1 are considered rare disorders, and may be diagnosed following incidental biochemical testing of asymptomatic individuals, or in the case of ADH1, following the presentation of an individual with symptomatic hypocalcemia.10, 11, 12 However, the prevalence of FHH1 or ADH1 remains to be determined in the general population.10, 11, 12, 13, 14. This evidence concerns the gene ADH1A and Hypocalcemia.