ALDH5A1 and succinic semialdehyde dehydrogenase deficiency: <h4>Background and aims</h4>To investigate the clinical features, ALDH5A1 gene variations, treatment, and prognosis of patients with succinic semialdehyde dehydrogenase (SSADH) deficiency.<h4>Materials and methods</h4>This retrospective study evaluated the findings in 13 Chinese patients with SSADH deficiency admitted to the Pediatric Department of Peking University First Hospital from September 2013 to September 2023.<h4>Results</h4>Thirteen patients (seven male and six female patients; two sibling sisters) had the symptoms aged from 1 month to 1 year.