Hyperparathyroidism results in excessive uptake and increased concentrations of calcium in serum leading to hypercalcemia and hypophosphatemia. This is then reflected in the urine as hypercalciuria and hyperphosphaturia. Thus, urine calcium levels are often increased in the setting of hyperparathyroidism.
What causes familial Hypocalciuric hypercalcemia?
Familial hypocalciuric hypercalcemia is an unusual, usually benign condition that causes chronically elevated serum calcium and reduced calcium excretion. It is typically caused by an abnormal set-point for parathyroid hormone (PTH) secretion in the calcium sensing receptor (CASR).
How is Fhh different from hyperparathyroidism?
The differentiation between FHH and primary hyperparathyroidism is more difficult in the absence of a family history of hypercalcemia if PTH levels are normal and if the Ca/Cr clearance ratio is greater than 0.01 and less than 0.02. The age at diagnosis of hypercalcemia and family history is important.
How is familial Hypocalciuric hypercalcemia treated?
As FHH is usually asymptomatic, treatment is not necessary. The hypercalcemia seen in FHH does not respond to diuretics or bisphosphonates. For those with constantly elevated serum calcium concentrations >14mg/dL or in those with NSHPT or relapsing pancreatitis, a total parathyroidectomy can be beneficial.
What is familial Hypocalciuric hypercalcemia?
Familial hypocalciuric hypercalcemia (FHH) is an inherited disorder that causes abnormally high levels of calcium in the blood (hypercalcemia) and low to moderate levels of calcium in urine (hypocalciuric). People with FHH usually do not have any symptoms and are often diagnosed by chance during routine bloodwork.
Does hyperparathyroidism cause calcium in urine?
A LOW calcium level in the urine associated with high PTH and high blood calcium means the patient has primary hyperparathyroidism. Period. FHH will not cause high blood calcium and high PTH!
Why does familial Hypocalciuric hypercalcemia have low urine calcium?
Pathogenesis. Most cases of FHH are associated with loss of function mutations in the calcium-sensing receptor (CaSR) gene, expressed in parathyroid and kidney tissue. These mutations decrease the receptor’s sensitivity to calcium, resulting in reduced receptor stimulation at normal serum calcium levels.
Is FHH life threatening?
Purpose of review: Hypercalcaemia is a potentially life-threatening condition. Familial hypocalciuric hypercalcaemia (FHH) is a rare, lifelong, benign condition. It is important to separate this condition from other hypercalcaemic states such as hypercalcaemia of malignancy and primary hyperparathyroidism (PHPT).
Does hyperparathyroidism cause high calcium levels?
In primary hyperparathyroidism, an enlargement of one or more of the parathyroid glands causes overproduction of the hormone. This causes high calcium levels in the blood, which can cause a variety of health problems. Surgery is the most common treatment for primary hyperparathyroidism.
Is high calcium in the blood hereditary?
Hereditary factors. A rare genetic disorder known as familial hypocalciuric hypercalcemia causes an increase of calcium in your blood because of faulty calcium receptors in your body. This condition doesn’t cause symptoms or complications of hypercalcemia.
Can FHH cause osteoporosis?
They don’t get osteoporosis or stones. They just have a higher “normal” calcium level in the blood. So if FHH is a genetic disease, we should be able to use modern technology to examine a patient’s DNA to find the bad gene that is responsible for this “higher normal” blood calcium level.
What is familial hypercholesterolemia characterized by?
Familial hypercholesterolemia (FH) is an inherited condition that results in high levels of low-density lipoprotein (LDL) cholesterol. This also results in high total cholesterol as well. Cholesterol is a waxy substance found in your cells that can be dangerous when it builds up on artery walls.
What are the lab values for hypercalcemia?
Laboratory Studies. Initial testing is directed at malignancy, hyperparathyroidism, and hyperthyroidism, the most common causes of hypercalcemia. The measurement of circulating PTH in the serum is the most direct and sensitive measure of parathyroid gland function. A reference range is 2-6 mol/L.
