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The atypical hemolytic uremic syndrome (aHUS) is a rare clinical entity, but it is the most common cause of acute kidney failure in kids. The disease is characterized by microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure, and it is associated with high morbidity and systemic involvement. We report here three cases of aHUS in infants presenting with prodromal respiratory symptoms, diarrhea, hemolytic anemia, thrombocytopeniaand acute renal failure. aHUS cases depict mutations in several genes: membrane cofactor protein (MCP) and complement factor H related proteins 1 and 5 (CFH, RP1 and PR5. Two our patients showed mutations in the genes CFH and MCP, and one presented a new non-previously reported mutation in the gen C3. Our results emphasize the existence of these aHUS mutations and underscore the need to study them to prevent morbidity and mortality. El síndrome hemolítico urémico atípico (SHUa) es una entidad clínica considerada rara; sin embargo, es la causa más común de insuficiencia renal aguda en niños. Esta enfermedad se acompaña de anemia hemolítica microangiopática, trombocitopenia, retención nitrogenada y afectación de la función renal, por lo que representa alta morbilidad y compromiso sistémico. Se reportan tres casos de SHUa en lactantes que presentaron pródromos respiratorios, diarrea, anemia hemolítica y trombocitopenia, con pérdida de función renal. Estos casos mostraron que dicha patología está asociada a mutaciones en los genes: CFH (Complemento Factor H), MCP (Membrana Cofactor Proteín), CFHR1 (Complemento Factor H-Related Proteín1), CFHR5 (Complemento factor H-Related Protein 5) y el gen C3 (Complemento component 3). Los genes CFH y MCP se encontraron afectados en dos de los casos, mientras que el tercer caso mostró una mutación nueva no reportada en el gen C3. Estos resultados evidencian que estas mutaciones están presentes en el Perú, por lo que se debe investigar y establecer medidas de prevención para reducir el alto riesgo de morbilidad y mortalidad que presentan los niños portadores SHUa.

Excreció; Genètica humana; Mutació Excreción; Genética humana; Mutación Excretion; Human genetics; Mutation Introduction Type III Bartter syndrome (BS) is an autosomal recessive renal tubule disorder caused by loss-of-function mutations in the CLCNKB gene, which encodes the chloride channel protein ClC-Kb. In this study, we carried out a complete clinical and genetic characterization in a cohort of 30 patients, one of the largest series described. By comparing with other published populations, and considering that 80% of our patients presented the p.Ala204Thr Spanish founder mutation presumably associated with a common phenotype, we aimed to test the hypothesis that allelic differences could explain the wide phenotypic variability observed in patients with type III BS. Methods Clinical data were retrieved from the referral centers. The exon regions and flanking intronic sequences of the CLCNKB gene were screened for mutations by polymerase chain reaction (PCR) followed by direct Sanger sequencing. Presence of gross deletions or duplications in the region was checked for by MLPA and QMPSF analyses. Results Polyuria, polydipsia and dehydration were the main common symptoms. Metabolic alkalosis and hypokalemia of renal origin were detected in all patients at diagnosis. Calciuria levels were variable: hypercalciuria was detected in 31% of patients, while 23% had hypocalciuria. Nephrocalcinosis was diagnosed in 20% of the cohort. Two novel CLCNKB mutations were identified: a small homozygous deletion (c.753delG) in one patient and a small deletion (c.1026delC) in another. The latter was present in compound heterozygosis with the already previously described p.Glu442Gly mutation. No phenotypic association was obtained regarding the genotype. Conclusion A poor correlation was found between a specific type of mutation in the CLCNKB gene and type III BS phenotype. Importantly, two CLCNKB mutations not previously described were found in our cohort This study was supported by two grants (PI09/90888 and PI11/01412) from the FIS of the Instituto de Salud Carlos III, Madrid, Spain, the Department of Health of the Basque Government (2014111064), and the Department of Education of the Basque Government (IT795-13).

Se presentan dos pacientes con síndrome nefrótico sensibles a corticoides y lesiones compatibles con Linfoma de Hodgkin. En uno se encontró una masa mediastinal en la evolución y en el otro un nódulo pulmonar. En ambos casos la biopsia mostró, a la microscopia óptica, hallazgos compatibles con linfoma de Hodgkin Luego de la quimioterapia presentaron remisión de la enfermedad renal.(Rev Med Hered 2011;22:182-185). We report two patients with Corticosensitive nephrotic syndrome and Hodgkin Lymphoma. In one case was found a mediastinal mass during its evolution and in the other, a lung nodule. In both cases, biopsy was performed and the results were consistent with Hodgkin Lymphoma. After chemotherapy had remission of renal disease.(Rev Med Hered 2011;22:182-185).

El Síndrome urémico hemolítico (SUH) tiene formas típicas y atípicas. Se describe una variedad de formas genéticas con pobre pronóstico. Presentamos un bebé prematuro de 36 semanas, de bajo peso al nacer, quien a las 2 semanas de vida cursó con sepsis y necrosis intestinal siendo sometido a cirugía para realizarle ileostomía. Evolucionó con hipertensión arterial, hematuria, falla renal aguda y proteinuria persistente. A los 2 meses de vida, posterior al cierre de ileostomía, cursó con shock séptico y falleció. La biopsia renal post mortem mostró cuadro compatible de SUH. Dos años después, un hermano debutó a los 2 días de vida con síndrome nefrótico congénito. El estudio genético reveló que la madre era portadora del gen NPHS1 y el padre, del Factor I de complemento. El segundo hijo era portador de ambos genes. (Rev Med Hered 2011;22:29-33). Hemolytic Uremic Syndrome (HUS) has typical and atypical presentations. A variety of genetic forms, with poor prognosis are described. We report a 36 week premature baby, low birth weight, who at 2 weeks of life evolved with sepsis and intestinal necrosis undergoing surgery for ileostomy, hypertension, hematuria, acute renal failure and persistent proteinuria. At 2 months, after ileostomy closure, developed irreversible septic shock and died. Post-mortem renal biopsy was compatible with HUS. Two years later, a brother presented after 2 days of birth with congenital nephrotic syndrome. Genetic studies revealed that the mother was carrying the gene NPHS1 and the father, factor I of complement. The second child was a carrier of both genes. (Rev Med Hered 2011;22:29-33).