A de novo heterozygous missense BSCL2 variant in 2 siblings with intractable developmental and epileptic encephalopathy

Purpose: We present the case of 2 siblings with profound refractory epilepsy and neurological regression that began at the ages of 3 and 6 months. Diagnosis remained elusive despite extensive metabolic and genetic workups, including use of a targeted next-generation sequencing panel for epilepsy gen...

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Detalles Bibliográficos
Autores: Fernández-Marmiesse A, Sánchez-Iglesias S, Darling A, O'Callaghan MM, Tonda R, Jou C, Araújo-Vilar D
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Fundació Sant Joan de Déu
Repositorio:r-FSJD. Repositorio Institucional de Producción Científica de la Fundació Sant Joan de Déu
OAI Identifier:oai:fsjd.fundanetsuite.com:p16496
Acceso en línea:https://fsjd.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=16496
Access Level:acceso abierto
Palabra clave:Whole exome sequencing
BSCL2
Seipin
Early infantile epileptic encephalopathy
Descripción
Sumario:Purpose: We present the case of 2 siblings with profound refractory epilepsy and neurological regression that began at the ages of 3 and 6 months. Diagnosis remained elusive despite extensive metabolic and genetic workups, including use of a targeted next-generation sequencing panel for epilepsy genes. Methods: Whole-exome sequencing was performed for the 2 siblings and their unaffected parents, in addition to fibroblast cell culture, RNA extraction and reverse-transcription, and cDNA PCR. Brain tissue from one of the siblings was collected post-mortem for neuropathological examination, including histology and immunohistochemistry. Results: Ade novo nucleotide change (c.566 T > A; p.(Met189Lys)) in exon 4 of the BSCL2 gene was detected in the 2 siblings, and confirmed by Sanger sequencing. This variant was absent in the parents and in a third, unaffected sibling. Conclusion: Given thede novo nature of the variant, its absence from public and in-house databases, our in silico pathogenicity predictions, and co-segregation of the variant with the disease phenotype, we believe that this novel variant is associated with the epileptic encephalopathy phenotype of the 2 siblings. Our findings provide the first evidence of an association between a heterozygous BSCL2 variant and developmental and early infantile epileptic encephalopathy. Further functional studies will be needed to elucidate the pathophysiological mechanisms underlying this new BSCL2-associated phenotype.