Utilidad del estudio genético en la hipercalcemia hipocalciúrica familiar en familias con presentaciones clínicas atípicas / Usefulness of genetic tests in familial hypocalciuric hypercalcemia with atypical clinical presentation

Tradicionalmente se ha pensado que las pruebas bioquímicas del metabolismo fosfocálcico permiten diferenciar el hiperparatiroidismo primario (HPT1) y la hipercalcemia hipocalciúrica familiar (HHF) pero hay casos de difícil diagnóstico incluso para clínicos experimentados. Nos planteamos como objetivo evaluar la validez de las pruebas diagnósticas de la HHF así como la correcta indicación del estudio genético. Pacientes y métodos Hemos realizado un estudio descriptivo de 2 familias con hipercalcemia y sospecha de HHF de características atípicas. En orina de 24h hemos valorado los índices de excreción urinaria de calcio (eliminación de calcio [CE], cociente calcio/creatinina [CR] y cociente aclaramiento de calcio/aclaramiento de creatinina [CCCR]), junto con las concentraciones séricas de PTH y 25 hidroxivitamina D. A los casos índices se les realizó el estudio genético. Resultados Una paciente presentó hipercalciuria franca y persistente con valores más concordantes con HPT1 que de HHF si consideramos, como proponen las guías, un CCCR inferior a 0,01 como indicativo de HHF y superior a 0,02 como HPT1. Al caso índice de la segunda familia se le extirpó un adenoma de paratiroides. En ambos casos índice, encontramos la misma mutación c. 164C>T (p.Pro55Leu) en el exón 2 en heterocigosis descrita como responsable de HHF. Conclusiones El diagnóstico definitivo de HHF en las guías clínicas actuales requiere confirmación genética, lo cual ha permitido en nuestro caso la detección de 2 familias con HHF y características clínicas atípicas. En nuestra opinión el uso racional de estas pruebas ante la sospecha de HFF puede evitar intervenciones quirúrgicas innecesarias y gastos excesivos en su monitorización (AU)

Objectives: Biochemical tests related to calcium and phosphorus metabolism have traditionally been considered as a reliable tool to differentiate familial hypocalciuric hypercalcemia (FHH) from primary hyperparathyroidism (PHPT). However, diagnosis may sometimes be difficult even for experienced clinicians. Our objective was to assess the accuracy of diagnostic tests in FHH and the circumstances in which genetic studies are required. Patients and methods: A descriptive study was conducted of two families with hypercalcemia and suspected atypical FHH. Urinary calcium excretion was measured in 24-hour urine using different tests (calcium excretion (CE), urinary calcium/creatinine clearance ratio (UCCR)),and serum PTH and 25-hydroxyvitamin D levels were tested. Index cases underwent genetic study. Results: One patient from the first family showed overt, persistent hypercalciuria with values more consistent with PHPT than with FHH if we consider, as proposed by guidelines, a UCCR lower than 0.01 as diagnostic of FHH and a value higher than 0.02 as diagnostic of PHPT. The index case of the second family underwent surgery for a parathyroid adenoma. Both cases had a mutation c. 164C>T (Pro55Leu) in exon 2 in heterozygosis. Conclusions: According to current clinical guidelines, definitive diagnosis of FHH requires genetic confirmation, which allowed in our case for detection of two families with FHH and atypicalclinical presentations. We think that rational use of genetic tests may avoid unnecessary surgery and excess monitoring costs (AU)

[Usefulness of genetic tests in familial hypocalciuric hypercalcemia with atypical clinical presentation]. / Utilidad del estudio genético en la hipercalcemia hipocalciúrica familiar en familias con presentaciones clínicas atípicas.

OBJECTIVES: Biochemical tests related to calcium and phosphorus metabolism have traditionally been considered as a reliable tool to differentiate familial hypocalciuric hypercalcemia (FHH) from primary hyperparathyroidism (PHPT). However, diagnosis may sometimes be difficult even for experienced clinicians. Our objective was to assess the accuracy of diagnostic tests in FHH and the circumstances in which genetic studies are required. PATIENTS AND METHODS: A descriptive study was conducted of two families with hypercalcemia and suspected atypical FHH. Urinary calcium excretion was measured in 24-hour urine using different tests (calcium excretion (CE), urinary calcium/creatinine clearance ratio (UCCR)), and serum PTH and 25-hydroxyvitamin D levels were tested. Index cases underwent genetic study. RESULTS: One patient from the first family showed overt, persistent hypercalciuria with values more consistent with PHPT than with FHH if we consider, as proposed by guidelines, a UCCR lower than 0.01 as diagnostic of FHH and a value higher than 0.02 as diagnostic of PHPT. The index case of the second family underwent surgery for a parathyroid adenoma. Both cases had a mutation c. 164C>T (Pro55Leu) in exon 2 in heterozygosis. CONCLUSIONS: According to current clinical guidelines, definitive diagnosis of FHH requires genetic confirmation, which allowed in our case for detection of two families with FHH and atypical clinical presentations. We think that rational use of genetic tests may avoid unnecessary surgery and excess monitoring costs.

Resistencia a la fludrocortisona en paciente con enfermedad de Addison y trastorno bipolar en tratamiento con litio / Causes resistance in patient with Addison disease and bipolar disorder treated with lithium

No disponible

Resistencia a la fludrocortisona en paciente con enfermedad de Addison y trastorno bipolar en tratamiento con litio / Causes resistance in patient with Addison disease and bipolar disorder treated with lithium

No disponible

Hepatotoxicidad inducida por paroxetina / Hepatotoxicity due to paroxetine

No disponible