Objective: We hypothesized that most patients with 22q11.2 deletion and a history of hypocalcemia have inadequate parathyroid function, manifested by intact parathyroid hormone levels below normal.

Photomicrograph of One of the Hyperplastic Parathyroid Glands, Showing Islands of Small, Dark Chief Cells Adjacent to Larger Cells with Clear Cytoplasm (X175). A night-time calcium-infusion test ...