Loss of <i>ap4s1</i> in zebrafish leads to neurodevelopmental defects resembling spastic paraplegia 52
Angelica D’Amore, Alessandra Tessa, Valentina Naef, Maria Teresa Bassi, Andrea Citterio, Romina Romaniello, Gianluca Fichi, Daniele Galatolo, Serena Mero, Roberta Battini, Giulia Bertocci, Jacopo Baldacci, Federico Sicca, Federica Gemignani, Ivana Ricca, Anna Rubegni, Jennifer Hirst, Maria Marchese, Mustafa Şahin, Darius Ebrahimi‐Fakhari, Filippo M. Santorelli
Abstract
Autosomal recessive spastic paraplegia 52 is caused by biallelic mutations in AP4S1 which encodes a subunit of the adaptor protein complex 4 (AP-4). Using next-generation sequencing, we identified three novel unrelated SPG52 patients from a cohort of patients with cerebral palsy. The discovered variants in AP4S1 lead to reduced AP-4 complex formation in patient-derived fibroblasts. To further understand the role of AP4S1 in neuronal development and homeostasis, we engineered the first zebrafish model of AP-4 deficiency using morpholino-mediated knockdown of ap4s1. In this model, we discovered several phenotypes mimicking SPG52, including altered CNS development, locomotor deficits, and abnormal neuronal excitability.