Two cases of 22q11.2 deletion syndrome with decreased serum calcium during recovery following thyrotoxicosis

The most common chromosomal microdeletion syndrome, 22q11.2 deletion syndrome (22qDS), mainly manifests as hypoparathyroidism, which varies from overt to subclinical presentation, and is often asymptomatic. 1 Parathyroid hormone (PTH) reserve, the response of PTH to the sodium bicarbonate infusion test, is reduced in many patients with 22qDS having normocalcemia. 2 22qDS is associated with high-autoimmune thyroid disease inci-dence. 3 Hypercalcemia due to thyrotoxicosis is rarely reported, which means that thyroid hormones affect calcium (Ca) metabolism. 4 22qDS hypocalcemia thyrotoxicosis 5 hypocalcemia and during thyrotoxicosis.