Familial Hypocalciuric Hypercalcemia (FHH)

Individuals with familial (benign) hypocalciuric hypercalcemia, type 1 (HHC1/FHH) are generally asymptomatic throughout life and do not require treatment. Affected individuals have mild or moderate elevations of calcium in serum, relative hypocalciuria, inappropriately normal serum parathyroid levels and may also have increased serum magnesium levels and a renal calcium/creatinine clearance ratio below 0.01, which differs from patients with primary hyperparathyroidism and other hypercalcemic disorders. Some patients experience pancreatitis, gall stones, renal stones, or chondrocalcinosis. Affected individuals may also have fatigue, weakness, mental disturbance, and polydipsia/polyuria. There is some evidence for an increased risk of diabetes mellitus and cardiovascular disease

Tests Available

Forms and Documents

Test Details

  • Distinguish FHH from primary hyperparathyroidism and other disorders of calcium homeostasis
  • Confirmation of a clinical diagnosis
  • To determine appropriate treatment, including avoidance of parathyroidectomy in FHH patients
  • Prenatal diagnosis in pregnancies at-risk for NSHPT
  • Capillary Sequencing


4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Dried Blood Spots|Buccal Swabs


  • 275.4 Disorders of calcium metabolism
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