Genetic Screening

Some people may have an increased chance of being a carrier of certain genetic diseases based on their ethnic backgrounds. Examples include:

• Cystic Fibrosis in Caucasians
• Sickle cell disease in African Americans
• Thalassemia in Asians and individuals of Mediterranean descent
• Tay-Sachs in Canavan disease in Ashkenazi Jews

Other people may be at risk for an inherited disorder present in their family. If you are concerned that your baby may be at risk for inheriting a disorder, talk with your healthcare provider. Your healthcare provider or a genetic counselor can discuss what screening options may be appropriate for you.

If you are at risk, a simple blood test may determine if you or your partner are carriers. If either of you are carriers, your healthcare provider or genetic counselor can discuss the risk to your baby of inheriting a disorder.

Cystic Fibrosis (CF)

Cystic Fibrosis is one of the most common inherited diseases. About 1 in 2,500 Caucasians in the United States has CF. Although it can occur in other ethnic groups, it is less common. CF causes the body to produce large amounts of abnormally thick mucus, which collects in the lungs and leads to congestion, pneumonia and lengthy hospitalizations. Mucus may also collect in the intestines, resulting in diarrhea and poor growth. Although present from birth, CF symptoms may not appear until a later time. CF does not affect intelligence, but it does greatly shorten life span. Presently, there is no cure for CF.

Sickle Cell Disease

Most sickle cell disease occurs among African Americans and Hispanics of Caribbean descent. About one in every 400 African Americans has sickle cell disease. Sickle cell is curable only in rare cases.

Sickle cell disease is an inherited disease of the red blood cells that can cause severe pain and damage to vital organs. Infants and young children with the disease are especially vulnerable to severe bacterial infections, the leading cause of death in sickle cell cases.

There are several forms of sickle cell disease. The most common forms are referred to as:

• SS: the child inherits two sickle cell genes
• SC: the child inherits one sickle cell gene and one gene for another abnormal type of hemoglobin (the oxygen-carrying part of the red blood cell)
• S beta-zero: the child inherits one sickle cell gene and one gene for a type of thalassemia, another inherited anemia

Thalassemia

Thalassemia occurs most frequently in people of Italian, Greek, Middle Eastern, Asian and African descent. Thalassemia includes a number of different forms of anemia (red blood cell deficiency). The two main types are called alpha and beta thalassemias, depending on which part of an oxygen carrying protein is lacking in the red blood cells.

Thalassemia major is the most harmful form. Most children born with this kind of thalassemia appear healthy at birth, but during the first year or two of life they become pale, listless, fussy, have a poor appetite and get many infections. Without treatment, the spleen, liver and heart soon become enlarged, bones become brittle, and the facial bones become distorted. Treatment consists of frequent blood transfusions to lessen the effects of the disease. Children born with thalassemia minor have very mild symptoms or none at all and require little to no treatment.

Tay-Sachs

Tay-Sachs occurs most often in descendants of Central and Eastern European (Ashkenazi) Jews and French Canadians. Tay-Sachs is a neurological disease that begins during infancy and gets worse over time. It is caused by a deficiency of the enzyme Hexosaminidase A (Hex A) necessary for breaking down certain fatty substances in brain and nerve cells. Without this enzyme, the entire central nervous system eventually stops working. Typically, a baby with Tay-Sachs develops normally for several months. Progressive deterioration then causes blindness, deafness, seizures and paralysis. Children do not usually live beyond the age of five. There is currently no treatment or cure for this disease.

Canavan

Canavan disease occurs most frequently in descendants of Central and Eastern European (Ashkenazi) Jews. Canavan is a progressive neurological disease caused by a deficiency of the enzyme Asparto-acyclase. This enzyme is crucial to the brain’s normal functioning. Typically, a baby with Canavan disease appears normal at birth. After several months of life, a progressive deterioration begins causing mental retardation, muscle weakness that develops into muscle stiffness, blindness, seizures and feeding problems. Children usually do not live beyond the age of 10. There is no cure or treatment for this disease.