Since the beginning of time, people have recognized the concept of inheritance – that is, the fact that traits are passed down from generation to generation. In most situations, those traits are viewed positively: She’s got her father’s eyes. He’s got his mother’s smile. But an inherited condition – one that causes birth defects or disease – invariably causes concern, and sometimes even fear. Positive or negative, these traits get passed on through “genes.”

What are Genes?

The easiest way to understand a gene is to think of it as a tiny piece of information. The body has tens of thousands of genes. Together, genes make up the molecular blueprint that determines how the body will develop, grow, and function. Genes do not float freely in the body; rather they are housed in molecular compartments know as chromosomes. If genes are the blueprints, chromosomes are the binders that hold the pages together and keep them organized. Humans have 23 pairs of chromosomes. Chromosomes, in turn are housed in cells. Thus virtually every cell in the human body is equipped with instructions that govern that cell’s activity.

More articles about Inherited Disorders and Birth Defects

• The Family Tree
• Genetic Disorders
• Genetics and Genetic Counseling
• Frequently Asked Questions About Genetic Counseling

For more information:

Go to the Inherited Disorders and Birth Defects health topic.