De novo mutations in EIF2B1 affecting eIF2 signaling cause neonatal/early onset diabetes and transient hepatic dysfunction

Permanent neonatal diabetes is caused by reduced β-cell number or impaired β-cell function. Understanding the genetic basis of this disorder highlights fundamental β-cell mechanisms. We performed trio genome sequencing for 44 permanent neonatal diabetes patients and their unaffected parents to identify causative de novo variants. Replication studies were performed in 188 patients diagnosed with diabetes before 2 years of age without a genetic diagnosis. EIF2B1 (encoding the eIF2B complex α subunit) was the only gene with novel de novo variants (all missense) in at least three patients. Replication studies identified 2 further patients with de novo EIF2B1 variants. In addition to diabetes, 4/5 patients had hepatitis-like episodes in childhood. The EIF2B1 de novo mutations were found to map to the same protein surface. We propose that these variants render the eIF2B complex insensitive to eIF2 phosphorylation which occurs under stress conditions and triggers expression of stress-response genes. Failure of eIF2B to sense eIF2 phosphorylation likely leads to unregulated unfolded protein response and cell death. Our results establish de novo EIF2B1 mutations as a novel cause of permanent diabetes and liver dysfunction. These findings confirm the importance of cell stress regulation for β-cells and highlight EIF2B1’s fundamental role within this pathway.Includes NIHR and Wellcome Trust. Wellcome Trust 200848/Z/16/

Tenofovir associated Fanconi's syndrome and rickets in a HIV infected girl

Introducción: El tenofovir (TDF) es un inhibidor de la transcriptasa reversa análogo de nucleótidos, aunque tiene buena tolerabilidad y alta actividad antirretroviral, su efecto sobre el riñón ha sido un motivo de preocupación. Objetivo: Describir el caso de una niña infectada por VIH que presenta síntomas y hallazgos de laboratorio compatibles con un síndrome de Fanconi durante el tratamiento con TDF como parte de su terapia antirretroviral. Caso clínico: Niña infectada por el VIH-1, que después de 18 meses con el tratamiento con TDF presentó pérdida de fuerza y dolor de las extremidades inferiores con deterioro funcional. Los hallazgos de laboratorio fueron compatibles con el síndrome de Fanconi. Las radiografías mostraron fractura bilateral de cadera y muñecas. El síndrome de Fanconi se recuperó por completo cuatro meses después del cambio de terapia antirretroviral. Conclusiones: Los médicos que prescriben TDF deben estar preparados para detectar signos y síntomas indicativos de disfunción renal y considerar de inmediato el cambio del fármaco a otro antirretroviral.Introduction: Tenofovir (TDF) is an inhibitor of reverse transcriptase nucleotide analogue, although it has good tolerability and high anti-retroviral activity, its effect on the kidney has been a concern. Objective: To describe a girl infected with HIV who presented Fanconi syndrome during antiretroviral therapy with TDF. Clinical case: We describe a HIV-1-infected girl, who after 18 months treatment with TDF presented loss of strength and pain of the lower extremities with functional impairment. Laboratory findings were consistent with Fanconi syndrome. Radiographs showed bilateral hip fracture and wrists. Full recovery of Fanconi syndrome was achieved four months after changing antiretroviral therapy. Conclusions: TDF-prescribing physicians must be prepared to detect signs and symptoms of renal dysfunction and immediately consider switching to another antiviral drug

De novo mutations in EIF2B1 affecting eIF2 signaling cause neonatal/early onset diabetes and transient hepatic dysfunction

Permanent neonatal diabetes is caused by reduced β-cell number or impaired β-cell function. Understanding the genetic basis of this disorder highlights fundamental β-cell mechanisms. We performed trio genome sequencing for 44 permanent neonatal diabetes patients and their unaffected parents to identify causative de novo variants. Replication studies were performed in 188 patients diagnosed with diabetes before 2 years of age without a genetic diagnosis. EIF2B1 (encoding the eIF2B complex α subunit) was the only gene with novel de novo variants (all missense) in at least three patients. Replication studies identified 2 further patients with de novo EIF2B1 variants. In addition to diabetes, 4/5 patients had hepatitis-like episodes in childhood. The EIF2B1 de novo mutations were found to map to the same protein surface. We propose that these variants render the eIF2B complex insensitive to eIF2 phosphorylation which occurs under stress conditions and triggers expression of stress-response genes. Failure of eIF2B to sense eIF2 phosphorylation likely leads to unregulated unfolded protein response and cell death. Our results establish de novo EIF2B1 mutations as a novel cause of permanent diabetes and liver dysfunction. These findings confirm the importance of cell stress regulation for β-cells and highlight EIF2B1’s fundamental role within this pathway.Includes NIHR and Wellcome Trust. Wellcome Trust 200848/Z/16/