Una nueva mutación de la enfermedad de Dent en un niño de 11 años con nefrolitiasis y nefrocalcinosis / A novel mutation of Dent's disease in an 11-year-old male with nephrolithiasis and nephrocalcinosis

La enfermedad de Dent es una tubulopatía recesiva ligada al cromosoma X caracterizada por proteinuria de bajo peso molecular (bpm), hipercalciuria, nefrocalcinosis o nefrolitiasis, disfunción tubular proximal e insuficiencia renal en la adultez. Las mujeres son portadoras y, en general, padecen una forma leve de la enfermedad. La progresión hacia la insuficiencia renal en estadio terminal se da entre los 30 y los 50 años de edad en el 30-80% de los varones afectados. A falta de un tratamiento dirigido al defecto molecular, en la actualidad, los pacientes con enfermedad de Dent reciben tratamientos complementarios orientados a prevenir la nefrolitiasis y la nefrocalcinosis. El caso que presentamos es el de un niño de 11 años con nefrocalcinosis y nefrolitiasis, en quien se detectó una nueva mutación en el gen CLCN5.

Dent's disease is a rare X-linked recessive tubulopathy characterized by low molecular weight (LMW) proteinuria, hypercalciuria, nephrolcalcinosis or nephrolithiasis, proximal tubular dysfunction and renal failure in adulthood. Females are carriers and usually mildly affected. Progression to endstage renal failure are at the 3rd-5th decades of life in 30-80% of affected males. In the absence of therapy targeting for the molecular defect, the current care of patients with Dent's disease is supportive, focusing on the prevention of nephrolithiasis and nephrocalcinosis. We present an 11-year-old child with nephrocalcinosis and nephrolithiasis caused by a new mutation at CLCN5 gene.

Antecedentes familiares y diagnóstico bioquímico en 1948 formadores de cálculos renales / Family history and biochemical diagnosis in 1948 kidney stone formers

INTRODUCTION: The presence of family history of nephrolithiasis is associated with an increased risk of renal lithiasis. Different epidemiological studies have shown a family component in the incidence of it, which is independent of dietary and environmental factors. The role of heredity is evident in monogenic diseases such as cystinuria, Dent's disease or primary hyperoxaluria, while a polygenic inheritance has been proposed to explain the tendency to form calcium oxalate stones. OBJECTIVE: Our objective was to evaluate the family history of patients with renal lithiasis and the correlation of family history with its corresponding biochemical alteration, considering only those with a single metabolic alteration. METHODS: a prospective and retrospective observational and analytical study that included 1948 adults over 17 years of age and a normal control group of 165 individuals, all evaluated according to an ambulatory protocol to obtain a biochemical diagnosis. They were asked about their family history of nephrolithiasis and classified into five groups according to the degree of kinship and the number of people affected in the family. RESULTS: a positive family history of nephrolithiasis was found in 27.4% of renal stone formers, predominantly in women, compared to 15.2% of normal controls. The family history of nephrolithiasis was observed especially in 31.4% of patients with hypomagnesuria and in 29.6% of hypercalciuric patients. The rest of the biochemical alterations had a positive family history between 28.6% in hyperoxaluria and 21.9% in hypocitraturia. The highest percentage of family history of nephrolithiasis was found in cystinuria (75%) although there were few patients with this diagnosis. CONCLUSIONS: the inheritance has a clear impact on urolithiasis independently of the present biochemical alteration. Family history of nephrolithiasis of the first and second degree was observed between 21 and 32% of patients with renal lithiasis, with hypercalciuria and hypomagnesuria being the biochemical alterations with more family history

INTRODUCCIÓN: La presencia de antecedentes familiares de nefrolitiasis se asocia con un mayor riesgo de litiasis renal. Diferentes estudios epidemiológicos han mostrado un componente familiar en la incidencia de la misma, que es independiente de los factores dietéticos y ambientales. El papel de la herencia es evidente en enfermedades monogénicas como la cistinuria, la enfermedad de Dent o la hiperoxaluria primaria, mientras que se ha propuesto una herencia poligénica para explicar la tendencia a la formación de cálculos de oxalato de calcio. OBJETIVO: Nuestro objetivo fue evaluar la historia familiar de los pacientes con litiasis renal y la correlación de los antecedentes familiares con su correspondiente alteración bioquímica, considerando solo aquellos con una única alteración metabólica. MATERIAL Y MÉTODOS: Estudio observacional y analítico prospectivo y retrospectivo que incluyó a 1948 adultos mayores de 17 años y un grupo control normal de 165 individuos, evaluados todos siguiendo un protocolo ambulatorio para obtener un diagnóstico bioquímico. Se les preguntó acerca de su historia familiar de nefrolitiasis y se clasificó en cinco grupos según el grado de parentesco y el número de personas afectadas en la familia. Resultados: Se encontró historia familiar positiva de nefrolitiasis en el 27,4% de los formadores de cálculos renales, predominando en mujeres, frente al 15,2% de los controles normales. La historia familiar de nefrolitiasis se observó especialmente en el 31,4% de los pacientes con hipomagnesuria y en el 29,6% de los hipercalciúricos. El resto de las alteraciones bioquímicas tuvo antecedentes familiares positivos entre el 28,6% en la hiperoxaluria y el 21,9% en la hipocitraturia. El porcentaje más alto de antecedentes familiares de nefrolitiasis se encontró en la cistinuria (75%) aunque hubo pocos pacientes con este diagnóstico. CONCLUSIONES: La herencia tiene un claro impacto en la urolitiasis independientemente de la alteración bioquímica presente. Se observan antecedentes familiares de nefrolitiasis de primer y segundo grado entre el 21 y 32% de los pacientes con litiasis renal, siendo la hipercalciuria y la hipomagnesuria las alteraciones bioquímicas con más antecedentes familiares

Uso a longo prazo de enalapril e hidroclorotiazida em dois pacientes com novas mutações com doença de Dent tipo 1 / The long-term use of enalapril and hydrochlorothiazide in two novel mutations patients with Dent's disease type 1

A doença de Dent é uma tubulopatia ligada ao X causada por mutações no gene que codifica o canal de cloro CLCN-5 e é caracterizada por proteinúria de baixo peso molecular, hipercalciúria, nefrocalcinose e insuficiência renal. Vários casos têm sido descritos, nos quais o único sintoma na apresentação foi proteinúria assintomática e glomerulosclerose global ou segmentar. A insuficiência renal nesses pacientes pode ser causada pela hipercalciúria e proteinúria persistente. Portanto, o inibidor da enzima de conversão da angiotensina e os tiazídicos poderiam ser úteis. O objetivo desta pesquisa é relatar os efeitos destas drogas em dois pacientes com doença de Dent tipo 1 com mutações novas. Neste relato não foram observadas correlações significativas entre dose de hidroclorotiazida e calciúria e entre enalapril e proteinúria. Este achado é importante, pois, sendo pacientes poliúricos, o uso destas drogas poderia prejudicar a função renal.

Dent's disease type 1 is an X-linked tubular disease caused by mutations in the renal chloride channel CLCN-5, and it is characterized by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis, and renal failure. Several cases have been described in which the only presenting symptoms were asymptomatic proteinuria, and focal segmental or global glomerulosclerosis. The renal failure in these patients may be caused by hypercalciuria and persistent proteinuria. Therefore, angiotensin converse enzyme inhibitor and thiazides could be useful. Our aim is to report the effects of these drugs in two novel mutations patients with Dent's disease type 1. In this report, no significant correlations between dosage of hydrochlorothiazide and calciuria and no significant correlations between proteinuria and dosage of enalapril were detected. This is important since these are polyuric patients and these drugs could be dangerous to their renal function.