AP4B1 hypomorphic variants cause autosomal recessive adult-onset ataxia.

Competing Interests: Declarations. Conflict of interest: The authors declare no conflict of interest. Ethical approval and consent to participate: We attest that the research included in this report was conducted in a manner consistent with the principles of research ethics, such as those described in the Declaration of Helsinki and/or the Belmont Report. In particular, this research was conducted with the voluntary, informed consent of any research participant, free of coercion or coercive circumstances, and received local Research Ethics Committee approval (CER-BDX 2023-164) consistent with the principles of research ethics and the legal requirements of the lead authors’ jurisdiction(s). Consent for publication: Not applicable.