WellSpan Home

Health Library

Autosomal Recessive: Cystic Fibrosis, Sickle Cell Anemia, Tay-Sachs Disease

We inherit genes from our biological parents in specific ways. One of the ways is called autosomal recessive inheritance.

What is autosomal recessive inheritance?

Autosomal recessive inheritance means that the gene in question is located on one of the autosomes. These are numbered pairs of chromosomes, 1 through 22. Autosomes do not affect an offspring's gender. "Recessive" means that 2 copies of the gene are necessary to have the trait or disorder. One is inherited from the mother, and 1 from the father. If you have only 1 recessive gene, you are a "carrier" for the trait or disease, but you do not have any health problems from "carrying" 1 copy of the gene. Most people do not know they carry a recessive gene for a disease until they have a child with the disease. It's estimated that all people carry about 5 or more recessive genes that cause genetic diseases or condition. Usually people do not know they carry a recessive gene, unless they have a child who is affected, or another family member. Once parents have had a child with a recessive trait or disease, there is a 1 out of 4, or a 25%, chance that with each subsequent pregnancy, another child will be born with the same trait or disorder. This means that there is a 3 out of 4, or a 75%, chance that another child will not have the trait or disease.

Genetic illustration demonstrating autosomal recessive inheritance

What are autosomal recessive disorders?

Mutations (or changes in the DNA) have occurred over time in different parts of the world. Anyone can carry any type of recessive gene. However, certain ethnic groups are more likely to carry certain recessive genes, because of where the mutation originated. For example, the gene that causes Tay-Sachs disease is found most commonly in people of Ashkenazi Jewish descent. This population is from eastern Europe, where experts believe the mutation originated. The disease also affects those who are not of Ashkenazi Jewish descent.

What are some of the different types of autosomal recessive disorders?

Examples of autosomal recessive disorders include cystic fibrosis, sickle cell anemia, and Tay-Sachs disease.

Cystic fibrosis

Cystic fibrosis (CF) is a common, inherited, single-gene disorder, in Caucasians. People with CF produce mucus that is abnormally thick and sticky that can damage body organs. The mucus interrupts the function of vital organs especially the lungs,  and leads to chronic infections. CF also involves the pancreas and causes decreased absorption of essential nutrients and reproductive system damage. With improved treatment and management of the disease,  affected people may live well into adulthood. Ultimately, death most often occurs from respiratory failure. Other people with variants of CF may have only lung involvement, sinusitis, or infertility.

Sickle cell anemia

Sickle cell anemia is another common, inherited, single-gene disorder in African-Americans. About 1 in 500 African-American babies is born with sickle cell anemia. About 1 in 12 African-American people carries the gene for this disease. Sickle cell disease involves the red blood cells, or hemoglobin, and their ability to carry oxygen. Normal hemoglobin cells are smooth, round, and flexible, like the letter "O." They can easily move through the vessels in our bodies. Sickle cells are stiff and sticky. When they lose their oxygen, they form into the shape of a sickle, or the letter "C." These sickle cells tend to cluster together and can't easily move through the blood vessels. The cluster causes a blockage and stops the movement of healthy, normal, oxygen-carrying blood. This blockage is what causes the painful and damaging complications of sickle cell disease.

Sickle cells live only for about 15 days. Normal hemoglobin cells can live up to 120 days. Sickle cells risk being destroyed by the spleen because of their shape and stiffness. The spleen helps filter the blood of infections. Sickle cells get "stuck" in this filter and die. Due to the decreased number of hemoglobin cells circulating in the body, a person with sickle cell is chronically anemic. The spleen also suffers damage from the sickle cells, which block the healthy oxygen-carrying cells. After repeated blockages, the spleen is very small and does not work properly. Without a functioning spleen, these people are more at risk for infections. Infants and young children are at risk for life-threatening infections. Treatment includes prompt emergency care for fevers and infections, appropriate vaccinations, penicillin, and management of anemia.

Tay-Sachs disease

Tay-Sachs disease is a fatal disorder in children (usually by age 5) that causes a progressive degeneration of the central nervous system. It is caused by the absence of an enzyme called hexosaminidase A (or hex A). Without hex A, a fatty substance builds up on the nerve cells in the body, particularly the brain. The process begins early in pregnancy when the baby is developing. It is not apparent until several months after the birth. To date, there is no cure for Tay-Sachs. About 1 in 27 persons of European Ashkenazi Jewish ancestry carries the Tay-Sachs gene.

Autosomal Recessive: Cystic Fibrosis, Sickle Cell Anemia, Tay Sachs Disease - WellSpan Health

Online Medical Reviewer: Haldeman-Englert, Chad, MD
Online Medical Reviewer: Sather, Rita, RN
Last Review Date: 2015-12-10T00:00:00
Last Modified Date: 2016-03-03T00:00:00
Posting Date: 2008-11-30T00:00:00
Published Date: 2016-03-03T00:00:00
Last Review Date: 2007-03-30T00:00:00
© 2016 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.


Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to https://my.wellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.