mucopolysaccharidosis: any of a group of genetic disorders involving a defect in the metabolism of mucopolysaccharides resulting in greater than normal levels of mucopolysaccharides in tissues
abstraction: a general concept formed by extracting common features from specific examples
nucleus: (astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail