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

CASR
  • 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

Ordering

170
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Dried Blood Spots|Buccal Swabs

Billing

81405x1
No
Yes
  • 275.4 Disorders of calcium metabolism
* For price inquiries please email zebras@genedx.com

References

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  2. Chou et al., (1995) Am J Hum Genet 56:1075-1079
  3. Pearce et al., (1995) J Clin Invest 96:2683-2692
  4. Pearce et al., (1996) NEJM 335(15):1115-1122
  5. Hendy et al., (2000) Hum Mut 16:281-296
  6. Hendy et al.,(2003) J of Clin Endocrin & Metab 88(8):3674-3681
  7. Warner et al., (2004) J Med Genet 41(3):155-60
  8. Lienhardt et al (2001) J Clin Endocr Metab 86:5313-5323
  9. Thakker (2004) Cell Calcium 35:275-28
  10. Gunn et al (2004) Ann Clin Biochem 41:441-58
  11. Simonds et al., (2002) Medicine (Baltimore) 81:1-26