RESUMEN
Purpose: FINCA disease (Fibrosis, Neurodegeneration and Cerebral Angiomatosis, OMIM 618278) is an infantile-onset neurodevelopmental and multiorgan disease. Since our initial report in 2018, additional patients have been described. FINCA is the first human disease caused by recessive variants in the highly conserved NHLRC2 gene. Our previous studies have shown that Nhlrc2-null mouse embryos die during gastrulation, indicating the essential role of the protein in embryonic development. Defect in NHLRC2 leads to cerebral neurodegeneration and severe pulmonary, hepatic and cardiac fibrosis. Despite having a structure suggestive of an enzymatic role and the clinical importance of NHLRC2 in multiple organs, the specific physiological role of the protein is unknown. Methods: The clinical histories of five novel FINCA patients diagnosed with whole exome sequencing were reviewed. Segregation analysis of the biallelic, potentially pathogenic NHLRC2 variants was performed using Sanger sequencing. Studies on neuropathology and NHLRC2 expression in different brain regions were performed on autopsy samples of three previously described deceased FINCA patients. Results: One patient was homozygous for the pathogenic variant c.442G > T, while the other four were compound heterozygous for this variant and two other pathogenic NHLRC2 gene variants. All five patients presented with multiorgan dysfunction with neurodevelopmental delay, recurrent infections and macrocytic anemia as key features. Interstitial lung disease was pronounced in infancy but often stabilized. Autopsy samples revealed widespread, albeit at a lower intensity than the control, NHLRC2 expression in the brain. Conclusion: This report expands on the characteristic clinical features of FINCA disease. Presentation is typically in infancy, and although patients can live to late adulthood, the key clinical and histopathological features are fibrosis, infection susceptibility/immunodeficiency/intellectual disability, neurodevelopmental disorder/neurodegeneration and chronic anemia/cerebral angiomatosis (hence the acronym FINCA) that enable an early diagnosis confirmed by genetic investigations.
RESUMEN
Fibrosis, neurodegeneration, and cerebral angiomatosis (FINCA, MIM#618278) is a rare clinical condition caused by bi-allelic variants in NHL repeat containing protein 2 (NHLRC2, MIM*618277). Pulmonary disease may be the presenting sign and the few patients reported so far, all deceased in early infancy. Exome sequencing was performed on patients with childhood interstitial lung disease (chILD) and additional neurological features. The chILD-EU register database and an in-house database were searched for patients with NHLRC2 variants and clinical features overlapping FINCA syndrome. Six patients from three families were identified with bi-allelic variants in NHLRC2. Two of these children died before the age of two while four others survived until childhood. Interstitial lung disease was pronounced in almost all patients during infancy and stabilized over the course of the disease with neurodevelopmental delay (NDD) evolving as the key clinical finding. We expand the phenotype of FINCA syndrome to a multisystem disorder with variable severity. FINCA syndrome should also be considered in patients beyond infancy with NDD and a history of distinct interstitial lung disease. Managing patients in registers for rare diseases helps identifying new diagnostic entities and advancing care for these patients.
Asunto(s)
Angiomatosis/diagnóstico , Angiomatosis/genética , Fibrosis/diagnóstico , Fibrosis/genética , Enfermedades Neurodegenerativas/diagnóstico , Enfermedades Neurodegenerativas/genética , Fenotipo , Alelos , Biopsia , Facies , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Inmunohistoquímica , Lactante , Recién Nacido , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Radiografía , Síndrome , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: FINCA disease is a pediatric cerebropulmonary disease caused by variants in the NHL repeat-containing 2 (NHLRC2) gene. Neurological symptoms are among the first manifestations of FINCA disease, but the consequences of NHLRC2 deficiency in the central nervous system are currently unexplored. METHODS: The orthologous mouse gene is essential for development, and its complete loss leads to early embryonic lethality. In the current study, we used CRISPR/Cas9 to generate an Nhlrc2 knockin (KI) mouse line, harboring the FINCA patient missense mutation (c.442G > T, p.Asp148Tyr). A FINCA mouse model, resembling the compound heterozygote genotype of FINCA patients, was obtained by crossing the KI and Nhlrc2 knockout mouse lines. To reveal NHLRC2-interacting proteins in developing neurons, we compared cortical neuronal precursor cells of E13.5 FINCA and wild-type mouse embryos by two-dimensional difference gel electrophoresis. RESULTS: Despite the significant decrease in NHLRC2, the mice did not develop severe early onset multiorgan disease in either sex. We discovered 19 altered proteins in FINCA neuronal precursor cells; several of which are involved in vesicular transport pathways and actin dynamics which have been previously reported in other cell types including human to have an association with dysfunctional NHLRC2. Interestingly, isoform C2 of hnRNP C1/C2 was significantly increased in both developing neurons and the hippocampus of adult female FINCA mice, connecting NHLRC2 dysfunction with accumulation of RNA binding protein. CONCLUSIONS: We describe here the first NHLRC2-deficient mouse model to overcome embryonic lethality, enabling further studies on predisposing and causative mechanisms behind FINCA disease. Our novel findings suggest that disrupted RNA metabolism may contribute to the neurodegeneration observed in FINCA patients.
Asunto(s)
Susceptibilidad a Enfermedades , Variación Genética , Ribonucleoproteína Heterogénea-Nuclear Grupo C/metabolismo , Hipocampo/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Neuronas/metabolismo , Alelos , Animales , Modelos Animales de Enfermedad , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Inmunohistoquímica , Ratones , Ratones Noqueados , Mapeo de Interacción de Proteínas , Mapas de Interacción de ProteínasRESUMEN
El rol monofuncional de la agricultura empresarial ha generado serios desequilibrios ambientales y socioculturales que comprometen su productividad futura. Una valoración de la multifuncionalidad de la agricultura en 18 sistemas tradicionales, ganaderos y de monocultivos, evaluados en la cuenca del río Guaguarco a partir de variables biofísicas, sociales, culturales, productivas y financieras, calificaron la agricultura tradicional como la más funcional, seguida de los sistemas ganaderos y de monocultivo. La capacidad de los agricultores para desplegar múltiples funciones en sus sistemas de finca constituye una estrategia para enfrentar las adversidades que ponen en riesgo su continuidad.
The monofunctional role of the business-oriented agriculture has generated serious environmental and socio-cultural imbalances that threaten its future productivity. An appraisal of agriculture's multifunctionality in 18 traditional farming systems, livestock farming and monoculture farming, evaluated at the Guaguarco river basin with biophysical, social, cultural, productive and financial variables, evaluated the traditional farming systems as the most functional followed by the livestock farming and monoculture farming. The farmer's capability to deploy multiple functions to their farming systems, constitute a strategy to face the adversities that put at risk continuity.