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.

The purpose of this study is to look at the safety and tolerability of RBX-121, a one-time gene therapy, in subjects with MPS II (Hunter Syndrome). You may be eligible for this study if you are a male between the ages of 4 months to 5 years old. Reimbursement for travel and research procedures will be provided. This study involves blood draws, interviews, urine collection, genetic testing, general anesthesia, lumbar punctures, MRI, gene therapy, lumbar puncture, ultrasound, ECG/echocardiogram and physical and neurological examinations. If you have questions or would like to learn more about the study, please contact the study team at MetabolismResearch@email.chop.edu.