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.
Familial isolated hypoparathyroidism (FIH) is an inherited metabolic disorder characterized by hypocalcemia and hyperphosphatemia due to deficient secretion of biologically active PTH.
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.
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).