Etiology and Differential Diagnosis of Hypercalcemia

Familial and Genetic Causes of Hypercalcemia: Syndromes and Diagnostic Criteria

Hypercalcemia is a condition characterized by elevated calcium levels in the blood. Understanding its etiology and differential diagnosis is crucial for effective management.

Common Causes of Hypercalcemia

• Primary Hyperparathyroidism
• Malignancy-Associated Hypercalcemia
• Vitamin D Toxicity
• Familial Hypocalciuric Hypercalcemia (FHH)

Familial and Genetic Syndromes

Some forms of hypercalcemia have a genetic basis. These include:

• Familial Hypocalciuric Hypercalcemia (FHH): Caused by mutations in the CASR gene, leading to altered calcium-sensing receptor function.
• Multiple Endocrine Neoplasia Type 1 and 2 (MEN1, MEN2): Genetic syndromes associated with endocrine tumors that can lead to hypercalcemia.
• Williams Syndrome: Characterized by congenital hypercalcemia due to excessive vitamin D sensitivity.

Diagnostic Criteria

Diagnosis of hypercalcemia involves assessing serum calcium levels, evaluating parathyroid hormone (PTH) levels, and genetic testing for familial syndromes.