Genetic diseases are those directly caused by specific, identifiable elements of a person's genetic makeup. Lysosomal storage disorders are one category of genetic diseases.

The organelles (smaller components within a cell) most relevant to lysosomal storage disorders are lysosomes, which are responsible for breaking down waste materials in cells.

Enzymes are a category of proteins responsible for speeding up chemical reactions to help regulate the body's development and function--for example, converting food into energy or breaking down waste substances in the lysosomes.

People's genetic information is contained within structures in the cell nuclei called chromosomes, which are constructed primarily of DNA molecules.

Every chromosome is divided up into thousands of genes.

Some genes control important activities, such as the production of vital enzymes needed for healthy functioning.

These genes are involved in lysosomal storage disorders (LSDs): people with these diseases have mutated forms of the genes responsible for producing enzymes that break down certain waste products. The mutated gene doesn't operate properly, so the enzymes malfunction or aren't produced in sufficient amounts.

If a gene mutation occurs in a sperm or egg cell, the mutated gene will get passed onto offspring during sexual reproduction. Since the offspring's very first cell carries the mutated gene, every subsequent cell replicated from it will also have the mutation.

If a person inherits an LSD-associated gene from both parents, he or she will develop the LSD.