Studies of States With Resistance to Vitamin D and Parathyroid Hormone

Completed

• Conditions: Rickets; Hypocalcemia; Pseudohypoparathyroidism; Pseudopseudohpoparathyroidism; Osteomalacia

• Registration Number: NCT00001242
• Lead Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Brief Summary

Patients with confirmed or suspected states with resistance to vitamin D or parathyroid hormone (PTH) will be admitted for diagnosis, treatment review with suggestions for modifications to the current or new treatment and for inclusion in other protocols. These states include hypocalcemia, rickets, osteomalacia, pseudohypoparathyroidism. Resistance to a factor is manifested by deficient bioeffect despite high levels of the factor in blood. Patients will be tested with multiple indices of mineral metabolism to establish the diagnosis and examine the spectrum of the underlying disorder. The principal therapies will be combinations of calcium, phosphate, and a vitamin D analog. Selected patients will have localization and surgery to remove a tumor that causes renal wasting of phosphate. Patients will also be considered for entry into other research protocols.

Detailed Description

Patients with confirmed or suspected states with resistance to vitamin D or parathyroid hormone (PTH) will be admitted for diagnosis, treatment review with suggestions for modifications to the current or new treatment and for inclusion in other protocols. These states include hypocalcemia, rickets, osteomalacia, pseudohypoparathyroidism. Resistance to a factor is manifested by deficient bioeffect despite high levels of the factor in blood. Patients will be tested with multiple indices of mineral metabolism to establish the diagnosis and examine the spectrum of the underlying disorder. The principal therapies will be combinations of calcium, phosphate, and a vitamin D analog. Selected patients will have localization and surgery to remove a tumor that causes renal wasting of phosphate. Patients will also be considered for entry into other research protocols.

Study Timeline

• Study Start: 1997-08-12
• Study First Submitted: 1999-11-03
• Study First Submitted QC: 1999-11-03
• Study First Posted: 1999-11-04
• Primary Completion: 2022-12-12
• Study Completion: 2022-12-12
• Status Verified: 2023-01
• Last Update Submitted: 2023-01-19
• Last Update Posted: 2023-01-20

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 70

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
This study will provide information about problems relating to calcium in the blood, urine, and bones	take one to two weeks	This is a natural history protocol, directed at diagnosing and managing the general clinical features in these patients. In addition the full clinical expression of certain rare disorders (target resistance to 1,25(OH)2D, pseudohypoparathyroidism, and pseudo- pseudohypoparathyroidism) will be characterized further. Some of these patients or their relatives will be entered into additional protocols, where appropriate for example, protocols to characterize the molecular causes of these disorders.

Trial Locations

Locations (1)

National Institutes of Health Clinical Center; 🇺🇸 Bethesda, Maryland, United States