Mutation of GATA3 has been previously reported in a developmental syndrome of hyperparathyroidism, deafness, and renal dysplasia (HDR syndrome).[9] GATA3 expression in hematopoietic cells is seen mainly in maturing and mature T cells and natural killer cells, it also plays an important role in the development of T lymphoid cell and immune regulation. The gene discussed is GATA3; the disease is hyperparathyroidism.