Q and A: about health and research

Overview Hypocalcemia refers to an abnormally low concentration of calcium in the blood. Calcium is essential for numerous physiological processes, including muscle contraction, nerve transmission, blood clotting, bone health, and maintaining a steady heartbeat. When calcium levels drop below normal, the nervous and muscular systems can become overly responsive, leading to symptoms ranging from mild tingling in the lips or fingertips to more severe issues such as muscle spasms, seizures, or abnormal heart rhythms. Autosomal Dominant Hypocalcemia Type 1 (ADH1) is a rare genetic disorder caused by a gain-of-function mutation in the CASR (Calcium-Sensing Receptor) gene. This mutation makes the receptor overly sensitive to calcium, causing it to signal the parathyroid glands to reduce secretion of parathyroid hormone (PTH), despite low calcium levels. This leads to persistent hypocalcemia and excessive loss of calcium in the urine (hypercalciuria). Autosomal Dominant Hypocalcemia Typ...