Mejía N, Santos F, Claverie-Martín F, García-Nieto V, Ariceta G, Castaño L; RenalTube group. RenalTube: a network tool for clinical and genetic diagnosis of primary tubulopathies. Eur J Pediatr. 2013 Jun;172(6):775-80. doi: 10.1007/s00431-013-1934-6. Epub 2013 Feb 7. PMID: 23389821.

The main purpose was to build a database while facilitating access to genotyping in order to improve the clinical and molecular knowledge of primary tubulopathies. Three tertiary referral centers of Spain collect clinical data through the site http://www.renaltube.com, while offering the analysis of 22 genes corresponding to 23 primary tubulopathies. There are three ways of collaboration: option 1 consists of adding patients to the database with clinical and biochemical information and requesting for genetic study, option 2 requires the payment of a fee for genetic analysis exclusively, and option 3 allows the enrollment of patients with a previously confirmed mutation. After 2 years of activity, RenalTube has collected data from 222 patients, the majority from Spain and Latin America (85.3 %). The most common tubulopathies are distal renal tubular acidosis (22.5 %) and classical Bartter syndrome (19.3 %) followed by familial hypomagnesemia with hypercalciuria and nephrocalcinosis (15.7 %) and Gitelman syndrome (15 %). Option 1 is the collaborating method preferred by doctors (62.3 %) followed by option 3 (36.3 %).

Conclusion: RenalTube is a network-based registry that can be easily reached and filled out worldwide. A web-based approach with a multilateral collaboration scheme enhances the recruitment of data and promotes the understanding of underlying mechanisms of rare inherited diseases, defines more accurate diagnostic and follow-up criteria, develops new molecular techniques and will improve the overall care of the patients.

Forero-Delgadillo JM, Gil-Peña H, Alonso-Varela M, Santos F; RenalTube Group. Kidney function in patients with primary distal renal tubular acidosis. Pediatr Nephrol. 2021 Jul;36(7):1931-1935. doi: 10.1007/s00467-021-05068-x. Epub 2021 Apr 8. PMID: 33834289

Background: Recent reports indicate that chronic reduction of glomerular filtration rate (GFR) is common in patients with distal renal tubular acidosis (DRTA). Factors responsible for decreased GFR need clarification.

Methods: We reviewed records of 25 patients with genetically confirmed DRTA included in the RenalTube database. Patients < 18 years at diagnosis and having at least one annual follow-up were selected and classified in two groups according to GFR ≥ 90 (normal GFR) or < 90 mL/min/1.73 m2 (low GFR) after median follow-up of 8.8 years.

Results: Eighteen and seven patients had normal and low GFR (X ± SEM, 121.16 ± 28.87 and 71.80 ± 10.60 mL/min/1.73 m2, respectively, p < 0.01). At diagnosis, these 2 subgroups did not differ in sex, age, underlying mutated gene, GFR, height SDS, or percentage of ultrasound nephrocalcinosis. Serum creatinine (SCr) was different but likely due to median ages of presentation being 0.6 and 4.0 in normal and low GFR patients, respectively. On the last recorded visit, no differences between both groups were found in serum bicarbonate, serum potassium, or alkali dosage. Height SDS of patients with normal GFR was – 0.15 ± 0.47 whereas it was – 1.06 ± 0.60 in the low GFR group (p = 0.27). Interestingly, 23% of the whole group had low birth weight (LBW; < 2500 g), equating to 20% and 29% in the normal and low GFR patients, respectively (p = 0.65).

Conclusions: Our findings confirm the risk of kidney function reduction in patients with DRTA of pediatric age onset, suggesting that low GFR is related with less favorable growth outcome and discloses the high frequency of LBW in primary DRTA, a hitherto unrecognized feature.

Nº expediente: PI20/00652
Entidad Financiadora: Instituto de Salud Carlos III y Fondo Europeo de Desarrollo Regional
Año de inicio y de finalización: 2021-2023
Investigador Principal: Félix Claverie Martín

Este proyecto busca mejorar la eficiencia del diagnóstico genético de varias tubulopatías renales incluidas en el proyecto coordinado RenalTube, investigar estrategias terapéuticas, y lograr una mayor aplicabilidad de RenalTube a las necesidades de los pacientes y sus familiares.
En este proyecto continuaremos el análisis genético de pacientes con tubulopatías, estudiaremos el potencial terapéutico del ácido tauroursodeoxicólico y el ácido docosahexaenoico en nuestro modelo de ratón knock-in (KI), valoraremos el efecto de oligos antisentido en el tratamiento de algunas enfermedades, examinaremos el posible efecto fundador de una mutación frecuente en los pacientes españoles con hipouricemia renal tipo 2, y en colaboración con las asociaciones de pacientes pretendemos conseguir una mayor aplicabilidad de RenalTube a las necesidades de los pacientes con enfermedad de Dent e hipomagnesemias familiares mediante la confección de acciones de transferencia entre RenalTube y dichas asociaciones.