ABCD syndrome, an uncommon cause of hypercalcemia in pediatrics. / Síndrome ABCD, una causa infrecuente de hipercalcemia en pediatría.

ABCD syndrome (ABnormal Calcium, Calcinosis, and Creatinine in Down syndrome) is characterized by an association of hypercalcemia, hypercalciuria, nephrocalcinosis, and impaired kidney function in patients with Down syndrome. Only 7 cases have been published worldwide, although it is believed to be underdiagnosed. This report describes 2 new patients with ABCD syndrome and compares them with the cases reported to date. Although it is a rare cause of pediatric hypercalcemia, it should be considered in children with Down syndrome once other more common etiologies have been ruled out. Once this diagnosis is confirmed, the recommended treatment is to reduce dietary calcium intake and work with an interdisciplinary team to maintain an adequate calorie and protein intake.

El síndrome ABCD (por sus siglas en inglés, ABnormal Calcium, Calcinosis and Creatinine in Down syndrome) se caracteriza por la asociación de hipercalcemia, hipercalciuria, nefrocalcinosis y alteración de la función renal en pacientes con síndrome de Down. Existen solo 7 casos previamente publicados en el mundo, aunque se cree que está subdiagnosticado. En este reporte, presentamos 2 nuevos pacientes con este síndrome y realizamos una comparación con los casos informados hasta el momento. Si bien es una causa rara de hipercalcemia pediátrica, debe considerarse en niños con síndrome de Down una vez descartadas otras etiologías más frecuentes. Al confirmarse este diagnóstico, el tratamiento recomendado es la reducción de calcio en la dieta, trabajando de manera interdisciplinaria para mantener un aporte calórico proteico adecuado.

A case of diffuse kidney hyperechogenicity in early childhood associated with biallelic PKHD1 variants.

BACKGROUND: Nephrocalcinosis (NC) is characterized by an excessive accumulation of calcium deposits in the kidneys. In children, it is often incidentally discovered with an uncertain prognosis. CASE-DIAGNOSIS/TREATMENT: A 3-month-old girl suspected to have a milk protein allergy underwent an ultrasound that revealed increased echogenicity in the kidney pyramids suggestive of medullary NC. At the age of 18 months, imaging findings revealed not only hyperechogenicity in the medulla but also in the cortex. Over the course of a long follow-up, her kidneys maintained size within the upper limits but showed an increase by age 7. Genetic analysis identified PKHD1 variants, which required structural predictive tools to guide clinical diagnosis. Until the age of 7, her kidney function has remained intact; however, her prognosis is uncertain. CONCLUSIONS: NC in newborns is a rare condition, but its incidence is rising. Recurrent urinary infections or kidney stones may lead to kidney failure. A proactive approach in sporadic NC enables an early diagnosis to orientate clinical supervision and facilitates counseling to support family planning decisions.

SHORT syndrome in an adult Brazilian patient.

We report an individual from Brazil with SHORT syndrome. The term SHORT stands for its common characteristics: short stature (S), hyperextensibility of joints, and/or inguinal hernia (H), ocular depression (O), Rieger anomaly (R), and teething delay (T). In addition to most of the clinical signs previously described in SHORT syndrome, the patient presented here also shows microcephaly and intellectual disability. Diagnosis was confirmed by exome sequencing revealing a novel heterozygous variant c.1456G>A (p.Ala486Thr) at PIK3R1. Human recombinant growth hormone (r-hGH) therapy was administered prior to diagnosis; however, the use of r-hGH may have had a role in anticipating and worsening the glucose metabolic profile in the patient, as previously described. This article contributes to providing a better understanding of the SHORT syndrome genotype and its correlation with the phenotype, by comparing with it other reported cases.

Insulin resistant diabetes mellitus in SHORT syndrome: case report and literature review.

SHORT syndrome is a rare developmental disorder frequently associated with growth failure and insulin resistant diabetes mellitus (IRDM). Since GH has a diabetogenic effect, GH therapy has been regarded as a contraindication. We observed a Brazilian girl with SHORT syndrome who received GH therapy from 4 6/12 years of age for SGA short stature. GH dosage was increased from 0.23 to 0.36 mg/kg/week, but statural response to GH therapy remained poor. Her blood HbA1c level, though it remained 5.5-6.0% in childhood, began to elevate with puberty and increased to 9.2% at 10 6/12 years of age, despite the discontinuation of GH therapy at 9 11/12 years of age. Laboratory studies indicated antibody-negative IRDM. She was treated with metformin and canagliflozin (a sodium glucose co-transporter 2 (SGLT2) inhibitor), which ameliorated overt diurnal hyperglycemia and mild nocturnal hypoglycemia and reduced her blood HbA1c around 7%. Whole exome sequencing revealed a de novo heterozygous pathogenic variant (c.1945C>T:p.(Arg649Trp)) in PIK3R1 known as the sole causative gene for SHORT syndrome. Subsequent literature review for patients with molecularly confirmed SHORT syndrome revealed the development of IRDM in 10 of 15 GH-untreated patients aged ≥12 years but in none of three GH-treated and six GH-untreated patients aged ≤10 years. These findings imply a critical role of pubertal development and/or advanced age rather than GH therapy in the development of IRDM, and a usefulness of SGLT2 inhibitor in the treatment of IRDM.

Bartter syndrome: An infrequent tubulopathy of prenatal onset. / Síndrome de Bartter: Una tubulopatía infrecuente de inicio antenatal.

INTRODUCTION: Bartter syndrome (BS) is a rare inherited tubulopathy that has two presentation forms, the first one is a severe form of antenatal onset (neonatal Bartter) and the second one is a later on set form during the first years of life (classic Bartter). In the antenatal form, it manifests with fetal polyuria, polyhydramnios of early and severe onset, premature delivery, and intrauterine growth restriction. In the postnatal stage, it presents recurrent episodes of dehydration and electrolyte im balance that can compromise the survival of the patient. OBJECTIVE: To report a clinical case of neo natal BS and a review of the literature. CLINICAL CASE: Premature newborn of 35 weeks of gestation with history of severe polyhydramnios diagnosed at 27 weeks of gestation, without apparent cause. From birth, the patient presented polyuria and hypokalemic metabolic alkalosis making a diagnosis of Neonatal Bartter Syndrome in the first week of life. Laboratory tests confirmed urinary electrolyte losses. The patient was treated with strict water balance and sodium and potassium supplementa tion, achieving weight and electrolyte imbalance stabilization. The patient remains in control in the nephrology unit, with potassium gluconate and sodium chloride supplementation. At the fourth month, ibuprofen was added as part of treatment. At the seventh month of life, renal ultrasound showed nephrocalcinosis. At one year of life, profound sensorineural hearing loss was observed re quiring a cochlear implant. CONCLUSION: The presence of severe polyhydramnios of early onset with no identified cause should lead to suspicion of neonatal BS which even when infrequent determines severe hydroelectrolytic alterations and should be treated early.

Síndrome de Bartter: una tubulopatía infrecuente de inicio antenatal / Bartter syndrome: an infrequent tubulopathy of prenatal onset

INTRODUCCIÓN: Síndrome de Bartter (SB) es una tubulopatía hereditaria, poco frecuente que tiene dos formas de presentación, forma grave de inicio antenatal (Bartter neonatal) y forma de aparición más tardía (Bartter clásico). En su forma antenatal se manifiesta con poliuria fetal, polihidroamnios de inicio precoz y severo, parto prematuro secundario y restricción de crecimiento intrauterino. La etapa postnatal presenta episodios recurrentes de deshidratación y desbalance electrolítico que pue den comprometer la sobrevida del paciente. OBJETIVO: Comunicar un caso de SB neonatal y presentar una revisión de la literatura en esta patología. CASO CLÍNICO: Prematuro 35 semanas, con antecedente de severo polihidroamnios diagnosticado a las 27 semanas de gestación, sin causa aparente. Desde su nacimiento evolucionó con poliuria y alcalosis metabólica hipokalémica haciendo plantear, en primera semana de vida, diagnóstico de Síndrome de Bartter neonatal. El laboratorio confirmó per didas urinarias de electrólitos. Fue manejado con balance hídrico estricto y suplementación de sodio y potasio, logrando estabilizar peso y desbalance electrolítico. Se mantiene en control nefrológico, con suplementación de gluconato de potasio y cloruro de sodio. Se agregó ibuprofeno al cuarto mes como parte del tratamiento. Al séptimo mes de vida, ecografía renal demostró nefrocalcinosis. Al año de vida se evidenció hipoacusia sensorioneural profunda requiriendo implante coclear. CONCLUSIÓN: Presencia de polihidroamnios severo de aparición temprana sin causa identificada debe hacer sospechar SB, que aun siendo infrecuente determina graves alteraciones hidroelectrolíticas y debe ser iniciado su tratamiento precozmente.

INTRODUCTION: Bartter syndrome (BS) is a rare inherited tubulopathy that has two presentation forms, the first one is a severe form of antenatal onset (neonatal Bartter) and the second one is a later on set form during the first years of life (classic Bartter). In the antenatal form, it manifests with fetal polyuria, polyhydramnios of early and severe onset, premature delivery, and intrauterine growth restriction. In the postnatal stage, it presents recurrent episodes of dehydration and electrolyte im balance that can compromise the survival of the patient. OBJECTIVE: To report a clinical case of neo natal BS and a review of the literature. CLINICAL CASE: Premature newborn of 35 weeks of gestation with history of severe polyhydramnios diagnosed at 27 weeks of gestation, without apparent cause. From birth, the patient presented polyuria and hypokalemic metabolic alkalosis making a diagnosis of Neonatal Bartter Syndrome in the first week of life. Laboratory tests confirmed urinary electrolyte losses. The patient was treated with strict water balance and sodium and potassium supplementa tion, achieving weight and electrolyte imbalance stabilization. The patient remains in control in the nephrology unit, with potassium gluconate and sodium chloride supplementation. At the fourth month, ibuprofen was added as part of treatment. At the seventh month of life, renal ultrasound showed nephrocalcinosis. At one year of life, profound sensorineural hearing loss was observed re quiring a cochlear implant. CONCLUSION: The presence of severe polyhydramnios of early onset with no identified cause should lead to suspicion of neonatal BS which even when infrequent determines severe hydroelectrolytic alterations and should be treated early.

Riñón en esponja y litiasis renal / Sponge kidney and renal lithiasis

Introducción: El riñón en esponja es una malformación renal, de los túbulos colectores, que se suele asociar a nefrocalcinosis o acidosis tubular distal. La asociación con la litiasis renal se observa entre un 4-20%. Objetivo: El objetivo de nuestro trabajo fue describir factores de riesgo bioquímicos para litiasis renales, en pacientes con riñón en esponja. Material y métodos: Se realizó un estudio retrospectivo, observacional de corte, entre los años 2000 y 2017 en donde se estudiaron 37 pacientes con riñón en esponja y litiasis renal (26 mujeres y 11 hombres) de 37.3 ± 13.2 años. El diagnóstico de riñón en esponja se hizo mediante urograma excretor. Resultados: Fue observada nefrocalcinosis en el 95%. El diagnóstico bioquímico más frecuente fue la hipercalciuria idiopática que como única y asociada alteración se observó en el 59.4%. La hiperuricosuria fue el segundo diagnóstico encontrado en el 32.4% (única y asociada) seguido por la, hipocitraturia, hipomagnesuria y el pHu persistentemente ácido. En los hombres llamó la atención que un 46.2% no presentaron alteración bioquímica. Conclusiones: En conclusión se destaca la asociación relativamente frecuente de riñón en esponja y litiasis renal. La hipercalciuria idiopática fue la alteración metabólica más frecuente como causa de litogénesis, seguida por la hiperuricosuria, similar a lo descripto en la literatura, aunque en menor proporción. Otras alteraciones, como la hipocitraturia, hipomagnesuria y pHu persistentemente ácido también deben ser consideradas en el estudio de estos pacientes.

Introduction: Sponge kidney is a renal malformation of the collecting tubules, which is usually associated with nephrocalcinosis or distal tubular acidosis. The association with renal lithiasis is observed between 4-20%. Objective: The aim of our work was to describe the biochemical risk factors of renal lithiasis in patients with sponge kidney. Methods: A retrospective, observational, cross-sectional study was conducted between 2000 and 2017, in which 37 patients with sponge kidney and renal lithiasis (26 women and 11 men), aged 37.3 ± 13.2 years, were studied. The diagnosis of sponge kidney was made by excretory urography. Results: Nephrocalcinosis was observed in 95% of patients. The most frequent biochemical diagnosis was idiopathic hypercalciuria, which was observed, as a single and associated alteration, in 59.4% of cases. Hyperuricosuria was the second diagnosis found in 32.4% (single and associated) followed by hypocitraturia, hypomagnesuria and persistently acid pHu. Surprisingly, 46.2% of men presented no biochemical alteration. Conclusions: Our findings highlight the relatively frequent association of sponge kidney and renal lithiasis. Idiopathic hypercalciuria was the most common metabolic alteration as the cause of lithogenesis, followed by hyperuricosuria, similar to that described in the literature, but to a lesser extent. Other alterations, such as hypocitraturia, hypomagnesuria and persistently acid pHu, should also be considered in the study of these patients.

[Nephrocalcinosis and proximal tubulopathy in Sjögren's Syndrome.] / Nefrocalcinosis y acidosis tubular renal proximal en síndrome de Sjögren.

Primary Sjögren's syndrome is a systemic and chronic autoimmune disease. Renal involvement may occur in up to 30% of patients. The incidence of tubulopathies ranges from 2.6 to 33%. They are manifested by defects in the urine concentration and hydroelectrolyte alterations, mainly distal tubular acidosis and exceptionally proximal tubular acidosis. These disorders can be associated with nephrocalcinosis and renal lithiasis. We report the case of a patient with primary Sjögren who presented proximal renal tubular acidosis associated with recurrent renal colic due to renal lithiasis and nephrocalcinosis. We highlight the importance of diagnosing renal tubular acidosis in patients with Sjögren's syndrome that present alterations in urinary sediment and electrolyte disorders to avoid nephrocalcinosis and nephrolithiasis. Acidosis correction treatment aims to prevent the progression of the disorder and preserve renal function.

El síndrome de Sjögren primario es una enfermedad autoinmune sistémica de evolución crónica. Puede presentar compromiso renal hasta en un 30% de los pacientes.La incidencia de tubulopatías varía de 2.6 a 33%. Se manifiestan por defectos en la concentración de la orina y alteraciones hidroelectrolíticas, principalmente acidosis tubular distal y de manera excepcional acidosis tubular proximal. Estos trastornos pueden asociarse a Nefrocalcinosis y litiasis renal. Reportamos el caso de una paciente con Sjögren primario que presentó acidosis tubular renal proximal asociada a cólicos renales recurrentes por litiasis renal y nefrocalcinosis. Destacamos la importancia de diagnosticar acidosis tubular renal en pacientes con síndrome de Sjögren que presenten alteraciones en el sedimento urinario y desórdenes electrolíticos para evitar la nefrocalcinosis medular y las nefrolitiasis asociadas. La terapia para la corrección de la acidosis tiene como objetivo evitar la progresión del trastorno y preservar la función renal.

Prevalence of Nephrocalcinosis in Pseudohypoparathyroidism: Is Screening Necessary?

The prevalence of nephrocalcinosis in persons with pseudohypoparathyroidism has not been systematically examined. We conducted a retrospective study of renal imaging and biochemical results in 19 patients with pseudohypoparathyroidism with 49 imaging assessments. No cases of nephrocalcinosis were identified. Routine screening for nephrocalcinosis in pseudohypoparathyroidism may not be necessary.

Enamel-Renal-Syndrome: case report.

AIMS: to describe a case in which dental changes were observed and investigation proceeded to consider Enamel-Renal-Syndrome (ERS), a rare disorder that associates amelogenesis imperfecta with nephrocalcinosis. CASE REPORT: an 11-year-old male patient upon intraoral examination revealed generalized gingival hyperplasia, a few teeth were absent clinically and the remaining ones were yellowish-brown in color. The enamel alterations were suggesting of amelogenesis imperfecta. Unerupted teeth with increased pericoronal spaces, suggesting hyperplasic follicles or dentigerous cysts and an enamel with lower thickness and density were observed in the panoramic radiography. The patient was referred for an assay to investigate mucopolysaccharidosis; however, it was negative. A renal ultrasound showed bilateral nephrocalcinosis and laboratory exams, including calcium, phosphate, and creatinine levels were below the average. An incisional gingival biopsy showed numerous round to ovoid basophilic calcifications in the connective tissue. The final diagnosis was ERS. CONCLUSION: Dentists should refer patients with similar clinical presentation for renal ultrasound evaluation in order to rule out the possible diagnosis of ERS.

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis: variable phenotypic expression in three affected sisters from Mexican ancestry.

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis is a rare autosomal recessive renal disease caused by mutations in genes for the tight junction transmembrane proteins Claudin-16 (CLDN16) and Claudin-19 (CLDN19). We present the first case report of a Mexican family with three affected sisters carrying a p.Gly20Asp mutation in CLDN19 whose heterozygous mother showed evident hypercalciuria and normal low magnesemia without any other clinical, laboratory, and radiological symptoms of renal disease making of her an unsuitable donor. The affected sisters showed variable phenotypic expression including age of first symptoms, renal urinary tract infections, nephrolithiasis, nephrocalcinosis, and eye symptoms consisting in retinochoroiditis, strabismus, macular scars, bilateral anisocoria, and severe myopia and astigmatism. End stage renal disease due to renal failure needed kidney transplantation in the three of them. Interesting findings were a heterozygous mother with asymptomatic hypercalciuria warning on the need of carefully explore clinical, laboratory, kidney ultrasonograpy, and mutation status in first degree asymptomatic relatives to avoid inappropriate kidney donors; an evident variable phenotypic expression among patients; the identification of a mutation almost confined to Spanish cases and a 3.5 Mb block of genomic homozygosis strongly suggesting a common remote parental ancestor for the gene mutation reported.

[Familial hypomagnesemia, hypercalciuria with nephrocalcinosis syndrome: report of a case]. / Síndrome de hipomagnesemia familiar con hipercalciuria y nefrocalcinosis: presentación de un caso.

Familial hypomagnesemia and hypercalciuria with nephrocalcinosis is a rare autosomal recessive disease characterized by renal calcium and magnesium wasting, evolving in the progressive decrease of renal function, eventually requiring kidney transplant. Clinical findings include urinary infection, polyuria, polydipsia, cramps, tremors, convulsions, among others; these, associated to ocular and/or auditive abnormalities. We present a 4 year-old female with the syndrome, which was manifested by typical signs and symptoms in daily practice: fever, abdominal pain, polyuria and polydipsia. These symptoms may defer the diagnosis of the syndrome.

Amelogenesis imperfecta and nephrocalcinosis syndrome: a case report and review of the literature.

Amelogenesis imperfecta (AI) is a group of hereditary disorders that affect the quality and/or quantity of dental enamel. This paper describes the clinicopathological features of a patient who was born of consanguineous parents and who presented with oral alterations, including yellow and misshapen teeth, intrapulpal calcifications, delayed tooth eruption, and gum enlargement. Scanning electron microscopy of the teeth revealed hypoplastic enamel, and a renal ultrasound detected bilateral nephrocalcinosis, leading to a diagnosis of AI and nephrocalcinosis syndrome. Since nephrocalcinosis is often asymptomatic and can be associated with impaired renal function, dentists who see children with generalized and thin hypoplastic AI should consider a renal ultrasound scan and referral to a nephrologist, if appropriate. Children with nephrocalcinosis should also be considered for a dental check.

Nefrocalcinose associada provavelmente com abuso de furosemida: relato de caso e revisão de literatura / Nephrocalcinosis probably associated with furosemide abuse: case report and review

Introdução: Nefrocalcinose tem sido descrita em neonatos e crianças que fazem uso de furosemida em altas doses por longo período de tempo. Relatamos aqui um caso de nefrocalcinose em uma mulher adulta após o uso de furosemida por dez anos. Relato de caso: Paciente de 27 anos, sexo feminino, admitida com queixa de edema, tendo feito uso de furosemida 40 a 120mg por dez anos. Ultra-sonografia diagnosticou nefrocalcinose, mostrando aumento difuso da ecogenicidade das pirâmides renais. Tratada com suspensão do furosemida. Evolução mostrou regressão do edema e nefrocalcinose persistente. Conclusão: Nefrocalcinose medular associada com abuso de furosemida por tempo prolongado em adulto é relatada e feita revisão de literatura sobre oassunto.

Introduction: Nephrocalcinosis has been described in neonates and infants who used furosemide in high doses for extended periods of time. We report here a case of nephrocalcinosis in an adult female after taking furosemide for ten years. Case report: A 27 year-old, female, admitted for edema took 40to 120 mg of furosemide per day for ten years. Nephrocalcinosis was diagnosed by ultrasonography, which showed a diffuse increase in echogenicity pyramids. Treatment was a furosemide suspension. Evolution showed regression of edema and persistent nephrocalcinosis. Conclusion: A case of medullary nephrocalcinosis associated with long-term furosemide abuse in adults is described and a review of the literature is presented.

Acidose tubular renal em pediatria: [revisão] / Renal tubular acidosis in pediatrics: [review]

O termo Acidose Tubular Renal (ATR) engloba diversas afecções caracterizadas por acidose metabólica secundária a um defeito na reabsorção tubular renal de HCO 3- e/ou na excreção urinária de H+, enquanto a função glomerular é nada ou minimamente afetada. Todas as formas de ATR apresentamacidose metabólica hiperclorêmica, com intervalo aniônico normal. São doenças crônicas com impacto significativo na qualidade de vida dos pacientesquando não tratadas adequadamente, podendo evoluir com déficit do crescimento, osteoporose, raquitismo, nefrolitíase e até perda da função renal.Podem ser primárias, decorrentes de defeitos genéticos nos mecanismos de transporte dos túbulos renais, ou secundárias a doenças sistêmicas ou aoefeito adverso de medicamentos. Neste artigo, é feita uma breve revisão da homeostase ácido-básica pelo rim, discutindo-se, a seguir, aspectos dafisiopatologia, diagnóstico e abordagem das acidoses tubulares renais em pediatria.

The term Renal Tubular Acidosis (RTA) defines many disorders characterized by metabolic acidosis, secondary to defects in renal tubular reabsorption ofHCO3 - and/or in urinary excretion of H+, while glomerular function is little or not affected. All forms of RTA present hyperchloremic metabolic acidosis, witha normal anion gap. When not adequately treated, these chronic diseases can have a significant impact on the quality of life of affected patients, and can evolve into growth failure, osteoporosis, rickets, nephrolithiasis and even renal insufficiency. These disorders can be primary, originating from genetic defectson tubular transport mechanisms, or can be secondary to systemic diseases and to adverse drug reactions. In this article, the mechanisms of acid-baseregulation by the kidney are briefly reviewed, followed by a presentation of the latest evidence regarding physiopathology, diagnosis and management ofrenal tubular acidosis in pediatric patients.

Nefrocalsinosis en niños / Nefrocalcinosis in children

Con el advenimiento de estudios de imagen altamente sensibles, como el ultrasonido y la tomografía computada, la nefrocalcinosis (NC) se diagnostica más frecuentemente. Mientras que en muchos casos la NC puede manifestarse de forma leve y reversible, en otros casos puede ser progresiva, causando inicialmente daño tubular y posteriormente daño glomerular. Por lo tanto, el diagnóstico temprano e intervención apropiada son de crucial importancia. Esta revisión abarcará aspectos de la NC en niños, incluyendo etiología, patogénesis, prevención y tratamiento(AU)

Nefrocalsinosis en niños / Nefrocalcinosis in children

Con el advenimiento de estudios de imagen altamente sensibles, como el ultrasonido y la tomografía computada, la nefrocalcinosis (NC) se diagnostica más frecuentemente. Mientras que en muchos casos la NC puede manifestarse de forma leve y reversible, en otros casos puede ser progresiva, causando inicialmente daño tubular y posteriormente daño glomerular. Por lo tanto, el diagnóstico temprano e intervención apropiada son de crucial importancia. Esta revisión abarcará aspectos de la NC en niños, incluyendo etiología, patogénesis, prevención y tratamiento