A genetic disease is a condition that is caused by an abnormality in the genes or chromosomes.

Chromosomes contain thousands of genes. Genes act as codes, or templates, that determine the structure of the body's essential building blocks: enzymes, proteins, hormones, etc.

An abnormality in any one chromosome, or a single gene, can result in disease. Tiny abnormalities in a single gene (or collection of genes) can cause an illness, or increase our risk for a certain disease. These abnormalities are referred to as mutations.