Exploring the Contribution of the Transporter AGT1/rBAT in Cystinuria Progression: Insights from Mouse Models and a Retrospective Cohort Study.

More than 20 years have passed since the identification of SLC3A1 and SLC7A9 as causative genes for cystinuria. However, cystinuria patients exhibit significant variability in the age of lithiasis onset, recurrence, and response to treatment, suggesting the presence of modulatory factors influencing cystinuria severity. In 2016, a second renal cystine transporter, AGT1, encoded by the SLC7A13 gene, was discovered. Although it was discarded as a causative gene for cystinuria, its possible effect as a modulatory gene remains unexplored. Thus, we analyzed its function in mouse models of cystinuria, screened the SLC7A13 gene in 34 patients with different lithiasic phenotypes, and functionally characterized the identified variants. Mice results showed that AGT1/rBAT may have a protective role against cystine lithiasis. In addition, among the four missense variants detected in patients, two exhibited a 25% impairment in AGT1/rBAT transport. However, no correlation between SLC7A13 genotypes and lithiasis phenotypes was observed in patients, probably because these variants were found in heterozygous states. In conclusion, our results, consistent with a previous study, suggest that AGT1/rBAT does not have a relevant effect on cystinuria patients, although an impact in patients carrying homozygous pathogenic variants cannot be discarded.

[Spanish bottled and tap water analysis and their relation with urinary lithiasis]. / Análisis de las aguas embotelladas y de grifo españolas y de las implicaciones de su consumo en la litiasis urinaria.

OBJECTIVE: To perform a chemical analysis of all the available waters in Spain with the idea of offering consume recommendations to lithiasic patients. MATERIAL AND METHODS: Information research of the chemical composition of Spanish tap and bottled water in publications, supermarkets and Internet. A descriptive study, and a correlation study between water components by means of Pearson test were performed. RESULTS: Information about composition from tap water of most of the main Spanish cities and 85 bottled water brands was found. A significant correlation between calcium and magnesium concentration (p = 0.0001) and high correlation between bicarbonate and sodium concentration (p = 0.0001, Pearson coefficient 0.958) was found. It is also offered water classifications according to calcium, bicarbonate, sodium and magnesium concentrations. CONCLUSION: A guideline about water election for lithiasic patients is offered according to their geographical origin and dietetic preferences, mainly lactic consume.

Análisis de las aguas embotelladas y de grifo españolas y de las implicaciones de su consumo en la litiasis urinaria / Spanish bottled and tap water analysis and their relation with urinary lithiasis

Objetivo: Realizar un análisis de la composición de las aguas disponibles en España para ofrecer unas recomendaciones de consumo a los pacientes litiásicos. Material y Métodos: Búsqueda de información sobre la composición de aguas de grifo y embotelladas en publicaciones, supermercados e Internet. Estudio descriptivo y de la correlación entre los distintos componentes mediante el coeficiente de correlación de Pearson. Resultados: Se obtuvo información sobre la composición de agua de grifo de la mayoría de capitales españolas y de 85marcas de agua embotellada. Se encontró una correlación entre la concentración de calcio y magnesio (p=0,0001) y una intensa relación entre la de bicarbonato y sodio (p=0,0001, coeficiente Pearson 0,958). Se ofrece clasificación de las aguasen función de la concentración de calcio, bicarbonato, sodio y magnesio. Conclusión: Se propone una guía de elección de agua del paciente litiásico en función de su procedencia geográfica y de sus preferencias dietéticas, principalmente el consumo de lácteos (AU)

Objective: To perform a chemical analysis of all the available waters in Spain with the idea of offering consume recommendations to lithiasic patients. Material and Methods: Information research of the chemical composition of Spanish tap and bottled water in publications, supermarkets and Internet. A descriptive study, and a correlation study between water components by means of Pearson test were performed. Results: Information about composition from tap water of most of the main Spanish cities and 85 bottled water brands was found. A significant correlation between calcium and magnesium concentration (p=0.0001) and high correlation between bicarbonate and sodium concentration (p=0.0001, Pearson coefficient 0.958) was found. It is also offered water classifications according to calcium, bicarbonate, sodium and magnesium concentrations. Conclusion: A guideline about water election for lithiasic patients is offered according to their geographical origin and dietetic preferences, mainly lactic consume (AU)