Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population

Peter H Nissen, Signe E Christensen, Lene Heickendorff, Kim Brixen, Leif Mosekilde

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

CONTEXT: The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE: We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS: A total of 213 subjects clinically suspected to have FHH, and 121 subjects enrolled as part of a family-screening program were studied. Genotype-phenotype relationships were established in 66 mutation-positive index patients and family members. MAIN OUTCOME MEASURES: We determined CASR gene mutations, and correlating levels of plasma calcium (albumin corrected), ionized calcium (pH 7.4), and PTH were measured. RESULTS: We identified 22 different mutations in 39 FHH families. We evaluated data on circulating calcium and PTH for 11 different mutations, representing a spectrum of clinical phenotypes, ranging from calcium concentrations moderately above the upper reference limit, to calcium levels more than 20% above the upper reference limit. Furthermore, the mean plasma PTH concentration was within the normal range in eight of 11 studied mutations, but mild to moderately elevated in families with the mutations p.C582Y, p.C582F, and p.G553R. CONCLUSIONS: The present data add 19 novel mutations to the catalog of inactivating CASR mutations and illustrate a variety of biochemical phenotypes in patients with the molecular genetic diagnosis FHH
Original languageEnglish
JournalJournal of Clinical Endocrinology and Metabolism
Volume92
Issue number11
Pages (from-to)4373-9
Number of pages7
ISSN0021-972X
DOIs
Publication statusPublished - 1. Nov 2007

Fingerprint

Calcium-Sensing Receptors
Mutation
Population
Primary Hyperparathyroidism
Reference Values

Keywords

  • Calcium
  • Codon
  • Computational Biology
  • DNA
  • Denmark
  • Gene Frequency
  • Humans
  • Hypocalcemia
  • Linear Models
  • Molecular Biology
  • Mutation
  • Parathyroid Hormone
  • Phenotype
  • Receptors, Calcium-Sensing
  • Variation (Genetics)

Cite this

@article{09666440c8ea11dc8674000ea68e967b,
title = "Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population",
abstract = "CONTEXT: The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE: We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS: A total of 213 subjects clinically suspected to have FHH, and 121 subjects enrolled as part of a family-screening program were studied. Genotype-phenotype relationships were established in 66 mutation-positive index patients and family members. MAIN OUTCOME MEASURES: We determined CASR gene mutations, and correlating levels of plasma calcium (albumin corrected), ionized calcium (pH 7.4), and PTH were measured. RESULTS: We identified 22 different mutations in 39 FHH families. We evaluated data on circulating calcium and PTH for 11 different mutations, representing a spectrum of clinical phenotypes, ranging from calcium concentrations moderately above the upper reference limit, to calcium levels more than 20{\%} above the upper reference limit. Furthermore, the mean plasma PTH concentration was within the normal range in eight of 11 studied mutations, but mild to moderately elevated in families with the mutations p.C582Y, p.C582F, and p.G553R. CONCLUSIONS: The present data add 19 novel mutations to the catalog of inactivating CASR mutations and illustrate a variety of biochemical phenotypes in patients with the molecular genetic diagnosis FHH",
keywords = "Calcium, Codon, Computational Biology, DNA, Denmark, Gene Frequency, Humans, Hypocalcemia, Linear Models, Molecular Biology, Mutation, Parathyroid Hormone, Phenotype, Receptors, Calcium-Sensing, Variation (Genetics)",
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Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population. / Nissen, Peter H; Christensen, Signe E; Heickendorff, Lene; Brixen, Kim; Mosekilde, Leif.

In: Journal of Clinical Endocrinology and Metabolism, Vol. 92, No. 11, 01.11.2007, p. 4373-9.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population

AU - Nissen, Peter H

AU - Christensen, Signe E

AU - Heickendorff, Lene

AU - Brixen, Kim

AU - Mosekilde, Leif

PY - 2007/11/1

Y1 - 2007/11/1

N2 - CONTEXT: The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE: We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS: A total of 213 subjects clinically suspected to have FHH, and 121 subjects enrolled as part of a family-screening program were studied. Genotype-phenotype relationships were established in 66 mutation-positive index patients and family members. MAIN OUTCOME MEASURES: We determined CASR gene mutations, and correlating levels of plasma calcium (albumin corrected), ionized calcium (pH 7.4), and PTH were measured. RESULTS: We identified 22 different mutations in 39 FHH families. We evaluated data on circulating calcium and PTH for 11 different mutations, representing a spectrum of clinical phenotypes, ranging from calcium concentrations moderately above the upper reference limit, to calcium levels more than 20% above the upper reference limit. Furthermore, the mean plasma PTH concentration was within the normal range in eight of 11 studied mutations, but mild to moderately elevated in families with the mutations p.C582Y, p.C582F, and p.G553R. CONCLUSIONS: The present data add 19 novel mutations to the catalog of inactivating CASR mutations and illustrate a variety of biochemical phenotypes in patients with the molecular genetic diagnosis FHH

AB - CONTEXT: The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE: We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS: A total of 213 subjects clinically suspected to have FHH, and 121 subjects enrolled as part of a family-screening program were studied. Genotype-phenotype relationships were established in 66 mutation-positive index patients and family members. MAIN OUTCOME MEASURES: We determined CASR gene mutations, and correlating levels of plasma calcium (albumin corrected), ionized calcium (pH 7.4), and PTH were measured. RESULTS: We identified 22 different mutations in 39 FHH families. We evaluated data on circulating calcium and PTH for 11 different mutations, representing a spectrum of clinical phenotypes, ranging from calcium concentrations moderately above the upper reference limit, to calcium levels more than 20% above the upper reference limit. Furthermore, the mean plasma PTH concentration was within the normal range in eight of 11 studied mutations, but mild to moderately elevated in families with the mutations p.C582Y, p.C582F, and p.G553R. CONCLUSIONS: The present data add 19 novel mutations to the catalog of inactivating CASR mutations and illustrate a variety of biochemical phenotypes in patients with the molecular genetic diagnosis FHH

KW - Calcium

KW - Codon

KW - Computational Biology

KW - DNA

KW - Denmark

KW - Gene Frequency

KW - Humans

KW - Hypocalcemia

KW - Linear Models

KW - Molecular Biology

KW - Mutation

KW - Parathyroid Hormone

KW - Phenotype

KW - Receptors, Calcium-Sensing

KW - Variation (Genetics)

U2 - 10.1210/jc.2007-0322

DO - 10.1210/jc.2007-0322

M3 - Journal article

VL - 92

SP - 4373

EP - 4379

JO - Journal of Clinical Endocrinology and Metabolism

JF - Journal of Clinical Endocrinology and Metabolism

SN - 0021-972X

IS - 11

ER -