The purpose of this study is to find out more about an investigational drug called mRNA-3927 (the study drug). An "investigational drug" is a drug that is being tested and is not approved by the U.S. Food and Drug Administration (FDA). We want to see how safe the study drug is and if it works for participants with propionic acidemia (PA).

This is an observational registry study intended to document the course of Lysosomal Acid Lipase Deficiency (LALD), in order to further understand the disease, its progression, which treatments are effective, and any related complications. As an observational study, no additional study visits - outside of subjects usual Metabolism clinic visit - are required. Eligible patients will be asked to sign an informed consent form prior to enrollment and will periodically have the option of completing questionnaires about their quality of life.