ABSTRACT Membranous nephropathy may present in any age group. While it is one of the most common causes of adult nephrotic syndrome, it is a rare histologic entity in the paediatric population. In adults it is more commonly classified as primary or idiopathic. In contrast, among children and adolescents, it is more frequently secondary to systemic disorders or drug exposures. One of the potentially implicated drugs is penicillamine, which has long been used as first-line therapy for symptomatic children with Wilson’s disease. We report a case of an adolescente treated with penicillamine for Wilson’s disease, who presented with overt nephrotic syndrome due to membranous nephropathy. As most of our knowledge about children and adolescents with membranous nephropathy has been based on extrapolations from adult studies, paediatric case reports may provide useful insights. We also aimed to emphasize the importance of proteinuria close monitoring in patients under treatment with penicillamine to allow for timely consideration of the drug withdrawal.

ABSTRACT Ureteral obstruction (ureteropelvic or ureterovesical junction obstruction) is frequently diagnosed during the workup investigation of na asymptomatic infant or child with upper urinary tract dilatation, commonly identified in a prenatal ultrasound. In older children, recurrent lumbar pain is a red flag for ureteral obstruction. Although less frequent, hypertension may be the initial and only manifestation of ureteral obstruction. The authors present two pediatric cases of unilateral ureteral obstruction with hypertension, in which the surgical treatment of the obstruction leads to blood pressure normalisation. In all pediatric age groups, a systematic investigation for secondary causes of hypertension is of paramount importance. In some cases, especially those of an obstructive nature, early surgical management can be curative, with normalization of blood pressure levels and prevention of renal injury.

Resumo O raquitismo fosfopênico pode ser causado por mutações no gene PHEX (ligado ao X do homólogo da endopeptidase que regula o fosfato). Atualmente, mais de 500 mutações no gene PHEX causam raquitismo hipofosfatêmico. Os autores relatam um caso clínico de uma menina de 4 anos com histórico familiar sem relevância, que apresentou falha no crescimento e arqueamento das pernas. Os exames laboratoriais mostraram hipofosfatemia, fosfatase alcalina elevada, cálcio normal, PTH levemente elevado e níveis normais de 25(OH)D e 1,25(OH)D. O estudo radiológico mostrou deformidades ósseas no rádio e no fêmur. O diagnóstico clínico do raquitismo fosfopênico foi realizado e o estudo genético detectou uma provável variante patogênica heterozigótica do gene PHEX: c.767_768del (p.Thr256Serfs*7). Esta variante não foi descrita anteriormente na literatura ou nas bases de dados. O conhecimento sobre novas mutações pode melhorar o desfecho de pacientes. A análise genética pode ajudar a estabelecer uma correlação genótipo-fenótipo.

Abstract Phosphopenic rickets may be caused by mutations in the PHEX gene (phosphate regulating endopeptidase homolog X-linked). Presently, more than 500 mutations in the PHEX gene have been found to cause hypophosphatemic rickets. The authors report a clinical case of a 4-year-old girl with unremarkable family history, who presented with failure to thrive and bowing of the legs. Laboratory tests showed hypophosphatemia, elevated alkaline phosphatase, normal calcium, mildly elevated PTH and normal levels of 25(OH)D and 1.25(OH)D. The radiological study showed bone deformities of the radius and femur. Clinical diagnosis of phosphopenic rickets was made and the genetic study detected a heterozygous likely pathogenic variant of the PHEX gene: c.767_768del (p.Thr256Serfs*7). This variant was not previously described in the literature or databases. Knowledge about new mutations can improve patient’s outcome. Genetic analysis can help to establish a genotype-phenotype correlation.

Pheochromocytoma and renal artery stenosis are surgically treatable causes of hypertension. Although rare, the coexistence of pheochromocytoma and renal artery stenosis has been described in case reports. Common pathophysiological mechanisms other than extrinsic compression may be involved in this association, such as catecholamine-induced vasospasm. The early recognition of the association of pheochromocytoma with renal artery stenosis is essential for appropriate treatment planning. We present the case of a previously healthy tenyear-old boy who presented with hypertensive encephalopathy, tachycardia and diaphoresis. Hypertension was found to be secondary to a catecholamine-producing tumor associated with coexisting renal artery stenosis. Hypertension resolved a few months after successful pheochromocytoma excision, without renal artery revascularization