Pregnancy in patients with end-stage renal disease on maintenance dialysis is uncommon, with annual incidences reported at 0.3 – 2.7%. Peritoneal dialysis usage in pregnancy has been less reported than hemodialysis, although outcomes are similar. Nowadays, there are insufficient data to establish a generalizable dialysis strategy in pregnant women with end-stage renal disease. As such, decisions should be individualized, depending on clinical factors, residual renal function, and, whenever possible, choice of the patient. We report the case of a 22-year-old patient receiving peritoneal dialysis who delivered a full-term, normal weight, healthy baby with increased dialysis dose achieved by supplementary hemodialysis during pregnancy, thus enabling peritoneal dialysis to be continued until the third trimester and minimizing hemodialysis requirements.

Dent’s disease is an X-linked recessive disease characterized by proximal tubulopathy with low-molecular weight proteinuria, hypercalciuria, nephrolithiasis, nephrocalcinosis, and kidney failure. It is mainly caused by mutations in the CLCN5 or OCRL1 genes, and only ~ 250 families have been identified with these mutations. We present a 31-year-old male referred to a nephrology consultation due to elevated serum creatinine and a history of nephrolithiasis. Complementary evaluation revealed protein/creatinine ratio of 1.9 g/g and albumin/creatinine ratio of 0.5 g/g, hypercalciuria and medullary nephrocalcinosis. These findings raised the suspicion of Dent’s disease, which was confirmed by genetic testing. A missense mutation in the CLCN5 gene (c.810C>G, p.(Ser270Arg)), not previously reported in populational databases, was identified. During the evaluation of the patient, it came to our attention that a first-degree male cousin was being followed in our kidney transplantation unit. Given the unknown etiology of his chronic kidney disease, genetic testing was performed, identifying the same mutation. This case highlights the importance of considering the diagnosis of Dent’s disease in the setting of a male patient with chronic kidney disease of unknown etiology, low-molecular-weight proteinuria, hypercalciuria, and nephrocalcinosis. Despite progression to end-stage kidney failure in a significant portion of male patients, there are no reports of recurrence after kidney transplantation.

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Gitelman syndrome (GS) is an autosomal recessive disease characterised by the presence of hypokalaemic metabolic alkalosis with hypomagnesaemia and hypocalciuria. The prevalence of this disease is 1–10/40 000. GS is usually associated with mild and non-specific symptoms and many patients are only diagnosed in adulthood. The disease is caused by mutations in the SLC12A3 gene. We present the case of a 49-year-old man referred to a nephrology appointment due to persistent hypokalaemia and hypomagnesaemia. Complementary evaluation revealed hypokalaemia, hypomagnesaemia, metabolic alkalosis, hyperreninaemia, increased chloride and sodium urinary excretion, and reduced urinary calcium excretion. Renal function, remainder serum and urinary ionogram, and renal ultrasound were normal. A diagnosis of GS was established and confirmed with genetic testing which revealed a novel mutation in SLC12A3 (c.1072del, p.(Ala358Profs*12)). This novel mutation extends the spectrum of known SLC12A3 gene mutations and further supports the allelic heterogeneity of GS.

Focal segmental glomerulosclerosis (FSGS) is a kidney histologic lesion that may be caused by multiple aetiologies and pathophysiological mechanisms, with podocyte injury and depletion as the common denominator. FSGS may be subdivided into different subclasses: primary, secondary, genetic and unknown forms. Notwithstanding the overlapping clinical and histological characteristics across the different forms of FSGS, their management and response to treatment are strikingly different. Genetic FSGS may be suggested by the appearance of nephrotic syndrome during childhood, but it may also present in adulthood, where the diagnosis is rather challenging due to widely variable clinical and histological phenotypes. Herein we present the case of a 34-year-old female with a family history of chronic kidney disease of undetermined aetiology, referred for a Nephrology consultation due to haematoproteinuria and de novo arterial hypertension. Complementary evaluation revealed a urinary protein/creatinine ratio of 4.3 g/g and albumin/creatinine ratio of 3.9 g/g with hypoalbuminaemia. Kidney biopsy revealed lesions of FSGS, associated with extensive foot process effacement. The constellation of findings and family history of kidney disease raised the suspicion of a genetic cause, therefore genetic testing was performed. Two variants in the NPHS2 gene [c.686G>A, p.(Arg229Gln) and c.855_856del, p(Arg286Thrfs*17)] were found in compound heterozygosity, compatible with the diagnosis of genetic FSGS. This case highlights the importance of a detailed evaluation of patients with FSGS lesions in order to identify the FSGS form, given its therapeutic and prognostic impact, including after kidney transplantation.