Abnormalities in the parathyroid hormone (PTH) gene as a cause of hypoparathyroidism were evaluated by linkage analysis with DNA polymorphisms adjacent to the PTH gene in 8 families in which members were affected with familial isolated hypoparathyroidism (FIH).
In summary, we observed a point mutation in the signal peptide-encoding region of a preproPTH gene in one FIH kindred and demonstrated a functional defect caused by the mutation.
Familial isolated hypoparathyroidism (FIH) is an inherited metabolic disorder characterized by hypocalcemia and hyperphosphatemia due to deficient secretion of biologically active PTH.
A preproparathyroid hormone allele from a patient with familial isolated hypoparathyroidism was shown to have a single point mutation in the hydrophobic core of the signal sequence.