Severe Symptomatic Hypercalcemia in a Patient With Familial Hypocalciuric Hypercalcemia

Area of Science:

• Endocrinology
• Genetics
• Internal Medicine

Background:

• Familial hypocalciuric hypercalcemia (FHH) is a rare, autosomal-dominant disorder characterized by mild hypercalcemia and low urinary calcium excretion.
• Typically, FHH presents asymptomatically or with mild symptoms, and rarely requires pharmacologic intervention.

Observation:

• A 76-year-old woman with a confirmed FHH type 1 mutation presented with symptomatic hypercalcemia.
• The symptomatic presentation was likely triggered by metabolic stressors associated with advanced age.

Findings:

• The patient exhibited significantly elevated serum calcium levels and parathyroid hormone, necessitating aggressive management.
• Treatment involved a multi-drug regimen including intravenous bisphosphonates, calcitonin, and cinacalcet.

Implications:

• This case underscores that even rare genetic conditions like FHH can manifest with severe symptoms in elderly individuals under metabolic stress.
• It highlights the importance of considering genetic predispositions in atypical presentations of hypercalcemia and the potential need for intensive therapeutic strategies.