The purpose of a Natural History StudyThere are two types of natural history studies: prospective and retrospective. A natural history study examines a group of people who have a specific medical condition or disease or are at risk of developing one. A natural history is non-interventional and collects health information in order to understand how the medical condition or disease develops and how to possibly treat it. No treatment or investigational product is given. In a prospective study, this data collection is forward-looking and is done over time in the future. In a retrospective study, researchers review and examine factors related to an outcome in the past by looking back on past exposures and medical events. of Late Infantile VariantA variant is a change in DNA. A variant may or may not cause disease. The following modifiers describe the variant: (i) pathogenic, (ii) likely pathogenic, (iii) uncertain significance, (iv) likely benign, or (v) benign depending on whether or not the variant causes disease. For example, a “pathogenic variant” may cause disease. The term “variant” has replaced the term “mutation.” CLN5 and CLN7 Disease is to better understand two rare forms of Batten diseaseBatten disease is the common name for a broad class of rare, inherited disorders or diseases of the nervous system also known as neuronal ceroid lipofuscinoses, or NCLs. In these diseases, a defect in a specific gene triggers a cascade of problems that interferes with a cell’s ability to recycle certain molecules. The disease has several forms that share some of the same features and symptoms but vary in severity and age when symptoms first begin to appear. Each form is caused by a variant in a different gene. Although “Batten disease” originally referred specifically to the juvenile-onset form of NCL, the term Batten disease is increasingly used to describe all forms of NCL. The disease ultimately leads to shortened lifespan.. It aims to:

• Understand and document the medical history, clinical characteristics, progression of symptoms, and medical events in individuals with CLN5 and CLN7.
• Provide greater understanding of clinically meaningful outcome measures to help inform endpoint selection for future clinical trialsA study conducted in humans that evaluates the effectiveness, safety, and side effects of investigational products (which could include medications, treatments, and devices) that have the possibility of treating a disease in that particular patient group..