P255: Gain-of-function CASR variants, a common genetic cause of non-surgical hypoparathyroidism: Findings from a sponsored genetic testing program

Hypoparathyroidism is a rare endocrine disorder characterized by insufficient or impaired production of parathyroid hormone, resulting in unbalanced mineral homeostasis and low serum calcium concentrations. Hypoparathyroidism is most frequently caused by injury to or removal of the parathyroid glands during surgery. With recent advancements in and increasing awareness of genetic testing, genetic etiologies have emerged as the second-leading cause of hypoparathyroidism. Genetic forms of hypoparathyroidism can present as isolated or as part of a syndrome and include disorders of parathyroid gland formation, parathyroid hormone secretion, and damage to the parathyroid gland through autoimmunity.