Lahey Health is now part of Beth Israel Lahey Health.  Explore Lahey locations below or reach Lahey Hospital & Medical Center, Beverly Hospital and Winchester Hospital.

General Genetics Information

Genes are units of inheritance that code for traits and conditions, such as eye color or hair texture. Genes are located on structures called chromosomes. Individuals typically have 46 chromosomes that come in 23 pairs. One copy of each chromosome pair (and therefore each gene) comes from our mother and the other from our father. Similarly, we pass on one copy of each chromosome pair to our children.

Genes make proteins that are necessary for the proper growth and development of the body. Each gene is made up of an informational code called DNA. If you think of a gene as a very large book, DNA is the alphabet that makes up the words and sentences in the book. When a gene is altered, it simply means there is a typographical error (typo) in the book. This alteration (or “mutation”) makes the gene unable to function properly. Alterations can be as large as an entire chapter missing from the book, or as small as a single letter change within a word.

Alterations in certain genes (called cancer predisposition genes) may increase an individual’s chance to develop specific types of cancer. Please review the following disease-specific information sheets for details about some of the more common hereditary cancer predisposition syndromes.

Genetic Discrimination Resources

Many individuals and families who see genetics providers have concerns about the privacy and confidentiality of their information and how genetic information might be used by third parties (insurance companies, employers, etc.). There is public concern about the possibility that a health insurance company or employer could use the results of a genetic test to discriminate against an individual. There are laws that exist to protect against genetic discrimination in the realms of health insurance and employment.

There are several websites that have additional information about genetic discrimination: