Heterozygous human GATA3 abnormalities predicting a loss of function, namely one nonsense mutation, two intragenic deletions, and two whole gene deletions, have been identified in several families with HDR syndrome, suggesting that the haplo-insufficiency of GATA3 is the major cause of the disease [20]. This evidence concerns the gene GATA3 and hypoparathyroidism-deafness-renal disease syndrome.