Studies of States With Resistance to Vitamin D and Parathyroid Hormone

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)70 enrolled

Overview

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 Type

OBSERVATIONAL

Enrollment

Conditions

Hypocalcemia Pseudohypoparathyroidism

Eligibility

Sex: ALLMin age: 2 MonthsMax age: 100 Years

Medical Language ↔ Plain English

* INCLUSION CRITERIA: Patients, from 2 months to 100 years of age, of either sex M or F, with vitamin D resistance, rickets, osteomalacia, pseudohypoparathyroidism, pseudo-pseudohypoparathyroidism, or suspicion of these or related disorders based upon the appropriateness of their problem to ongoing investigations. Current investigations are focused principally upon the inclusion of subjects with, or suspected of having, hypocalcemia likely due to a resistance to parathyroid hormone, including subjects who have a diagnosis, or likely diagnosis, of pseudohypoparathyroidism or pseudopseudohypoparathyroidism.

Outcomes

Primary Outcomes

This study will provide information about problems relating to calcium in the blood, urine, and bones

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.

Time frame: take one to two weeks