The difficulty with or loss of muscle coordination and bodily movements.


Inheritance characteristic where a gene is located on a numbered, non-sex chromosome. These are found on one of the 22 pairs of (44 total) autosomal chromosomes in a human body where DNA is stored. This is one of several ways that a trait, disorder, or disease can be passed down through families. These chromosomes are not the sex (X or Y) chromosomes.


Any chromosome in a cell that is not an X or Y sex chromosome. The average person has 22 pairs of autosomes (44 autosomes in total) in each cell that define the genetic make-up, or DNA, of the being. These chromosomes store thousands of genes and they are inherited from the beings’ parents. In addition to the 22 pairs of autosomes (44 total), beings also have one pair (2 total) sex chromosomes (X and Y in a male, and X and X in a female).


Long and single nerve-cell process that usually conducts impulses away from the cell body.

Batten disease

Batten 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.

Benign variant

When a variant has no impact on health and is recognized as a neutral variant.

Clinical trial

A 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.


Tightening in or around a joint that occurs when muscles surrounding the joint weaken and other muscles remain strong or increase in strength to accommodate the weakness. Joint contractures are more common in the feet, ankles, hips, hands, and wrists.