Abstract

MERINO, M. et al. Familial hypocalciuric hypercalcemia: sometimes it is not what it seems. Rev Osteoporos Metab Miner [online]. 2015, vol.7, n.1, pp.20-22. ISSN 2173-2345.  https://dx.doi.org/10.4321/S1889-836X2015000100005.

Familial hypocalciuric hypercalcemia (FHH) is an uncommon cause of hypercalcemia. Its prevalence is estimated to be 1:78,000 people. We describe a case with atypical presentation confirmed by genetic diagnosis. This is a case of a woman of 74 years of age with osteoporosis referred to the endocrinology service with suspected primary hyperparathyroidism (HPTP). She presented with a high level of parathyroid hormone (96.3 pg/ml, normal limits (NL): 15-65 pg/ml), with normal levels of calcium, phosphorus and magnesium, as well as a raised level of calciuria. She subsequently presented with normal levels of PTH, raised levels of calcium, combined with normal -high calciuria. The calcium/creatinine clearance ratio (CCCR, in mmol/l) varied between 0.011 and 0.02 mmol/l. A CCCR <0.01 is suggestive of FHH, and a CCCR >0.02, of HPTP. This ratio is within the range between 0.01 and 0.02 mmol/l, a reason which justifies requesting a genetic test in all patients with normal or high PTH, hypercalcemia and CCCR <0.02, requirements which our index case meets.

Keywords : familial hypocalciuric hypercalcemia; primary hyperparathyroidism; CaSR; calcium/creatinine clearance ratio (CCCR).

        · abstract in Spanish     · text in English | Spanish     · English ( pdf ) | Spanish ( pdf )