Trial Information

Family Studies in Metabolic Diseases and Mineral Metabolism

Familial multiple endocrine neoplasia type 1 (MEN1), familial hypocalciuric (or familial
benign) hypercalcemia (FHH), hyperparathyroidism - jaw tumor syndrome (HPT-JT), other causes
of familial isolated hyperparathyroidism (FIH), and pseudohypoparathyroidism (PHP) are
disorders of metabolism that are generally inherited in an autosomal dominant fashion. MEN1
is characterized by overgrowth and hyperfunction of the parathyroids, anterior pituitary and
gastrointestinal endocrine tissue. The gene for MEN1 was cloned in 1997. P15, p18, p 21 are
other genes for MEN1-like states. FHH is characterized by a usually benign syndrome
sometimes mistaken for typical primary hyperparathyroidism, which may result in unnecessary
and unsuccessful parathyroid surgery. The CASR gene for the calcium-sensing receptor of the
parathyroid cell was cloned, and members of most FHH kindreds have mutations in this gene.
HPT-JT is a distinctive subtype of familial isolated hyperparathyroidism (FIH) that has
combinations of parathyroid adenoma, parathyroid cancer, jaw tumor, kidney tumor and kidney
cysts. It is caused by mutation of the HRPT2 gene. PHP is characterized by parathyroid
hormone resistance, and one form is associated with mutations in the gene encoding the
stimulatory G protein. We are continuing to collect blood and tissue samples from affected
and unaffected members of known and suspected MEN1, FHH, HPT-JT, FIH, PHP, and related
kindreds for the purpose of genetic analysis and gene identification. In most cases, the
procurement of specimens will be at an off-site location. Samples will be processed for
extraction of DNA and RNA.