Moreover, we identified an unreported variant in the SPG3A causative gene ALT1. SPG3A is the most common early-onset AD-HSP, presenting with slowly progressive p-HSP with an AAO usually less than 10 years, and is the second most frequently found in AD-HSP patients in China (Giordani et al., 2021; Kelly et al., 2022). This evidence concerns the gene ATL1 and Alzheimer disease.