Autosomal recessive in children

Some health problems are hereditary. This can happen in different ways. In order to have a child with a so-called "autosomal recessive disease" such as sickle cell anemia or cystic fibrosis, you and your partner must both have a mutated (altered) gene that you pass on to your child.

How does this affect people?

Nearly every cell in your body contains 23 tightly folded pairs of DNA called chromosomes. You get 23 from your mother and 23 from your father.

A pair of chromosomes determines your gender. Others contain thousands of different genes that determine every other trait you have, from hair and eye color to disease risk. They are called autosomes.

Some genes are "dominant". You only need one parent to have this trait. Other genes are "recessive". With them, you must inherit the same gene from both parents to be affected.

If one of your parents passes you a recessive gene that can cause the disease, you become a "carrier". You probably won't have any symptoms as the other gene is normal. In fact, many people don't know they are carriers until they get tested.

But if you and your partner both have the same mutated gene, there is a 25 percent chance that your baby will be born with a serious disease.

Anyone can be a carrier of the recessive gene that causes the disease, but some diseases are more common in certain ethnic groups.

What are some types of these diseases?

Common autosomal recessive diseases include:

Sickle cell anemia: Sickle cell anemia makes your red blood cells stiff and sticky, so they can't move oxygen around your body easily. This puts you at risk for painful complications and serious infections.
Cystic fibrosis: People with this condition produce very thick mucus that sticks to the lungs and damages major organs. Cystic fibrosis also makes it difficult for the body to digest and absorb food.
Tay-Sachs disease: causes severe damage to the central nervous system. It most often occurs in people whose ancestry is Ashkenazi Jewish, French Canadian, Amish, or Cajun.
Gaucher disease: many of your organs and tissues can be damaged by this disease. Liver and spleen enlargement and anemia are common. Some people also have seizures and brain damage. The most serious type causes problems in babies before they are born or in the first days after birth.

Many autosomal recessive diseases seriously affect a child's life. In some cases, they can be fatal.

Who should be tested and when?

Screening for many autosomal recessive diseases is available. You can get tested if you have a high chance of being a carrier for a disease, or if you just want to know your risk of having a child with one of these diseases. DNA testing can check if you and your partner carry one of the mutated genes that could cause your baby to get sick. This can be done by taking a blood sample or by gently scraping the cells from your mouth.

If you are already pregnant, you can check the health of your baby. In outpatient procedures, such as amniocentesis and chorionic villus sampling, fluid or tissue in the uterus is checked to see if your baby has signs of any of these conditions.

Newborns can also be screened for severe autosomal recessive disorders shortly after birth.

What if the results are positive?

If your results show that you can pass on an autosomal recessive disease to your child, you may want to speak to a genetic counselor. This is a person trained to understand the medical problems that exist in families. They can help you understand the test results and what to do next.

A genetic counselor can also help you if your child was born with an autosomal recessive disorder. They can provide you with information, find doctors who can help treat your child's condition, and put you in touch with support groups. This can help you talk to other parents whose child has the same health problem.