Accessibility

Genetic Screening

Current genetic screening tests performed on our donors:

  1. CYSTIC FIBROSIS MUTATION ANALYSIS
    Cystic fibrosis (CF) is an autosomal recessive condition that is more common among Caucasian individuals. The carrier rate among healthy Northern European or Ashkenazi Jewish individuals is approximately 1 in 25. Individuals affected with CF have a chronic illness that typically includes severe lung disease and gastrointestinal problems that result in a shortened lifespan. All donors, regardless of ethnicity, are screened to see if they are carriers for CF.
  2. HEMOGLOBIN EVALUATION (complete blood count)
    All donors undergo a blood test called a complete blood count. This is a screening test that looks at the size, shape and amount of a person’s blood cells. This type of screening will detect some, but not all, individuals who carry alterations in their hemoglobin that could cause genetic conditions alpha-thalassemia or beta-thalassemia in their offspring. The thalassemias are autosomal recessive genetic disorders that are part of a spectrum of diseases called the hemoglobinopathies, a group of illnesses that affect hemoglobin. Hemoglobin is responsible for carrying oxygen to the cells of our bodies. Individuals affected with thalassemia generally have a severe anemia, and may require frequent blood transfusions and other medical surveillance and intervention over the course of their lifetimes. Some types of thalassemia may result in a shortened lifespan, or may result in fetal demise or death in infancy.

The following carrier screening is performed on donors that have any Jewish or French Canadian ancestry:

  1. TAY-SACHS DISEASE ENZYME ANALYSIS
    Tay-Sachs disease is an autosomal recessive condition that is more common among individuals with Ashkenazi Jewish or French Canadian ancestry. The carrier frequency in individuals of Ashkenazi Jewish descent is approximately 1 in 30. Tay-Sachs disease is a progressive neurological disorder that begins in infancy with the loss of developmental milestones and typically results in death by age 5, although some children will survive longer. Only our donors with Jewish or French Canadian ancestry are screened to see if they are carriers of Tay-Sachs disease.

The following carrier screening is performed on donors that have any Jewish ancestry:

  1. CANAVAN DISEASE MUTATION ANALYSIS
    Canavan disease is an autosomal recessive condition that is more common among individuals of Ashkenazi Jewish ancestry. The carrier frequency in this population is approximately 1 in 40. Canavan disease symptoms may vary from person to person, and the onset of symptoms can occur at different stages of life. The most common clinical type occurs in infancy, with death occurring in early childhood. Affected infants have mental retardation, seizures and other neuromuscular problems.
  2. FAMILIAL DYSAUTONOMIA MUTATION ANALYSIS
    Familial dysautonomia is an autosomal recessive condition that is more common among individuals of Ashkenazi Jewish ancestry. The carrier frequency in this population is approximately 1 in 30. Familial dysautonomia is a disorder of the nervous system, characterized by insensitivity to pain, episodes of vomiting and sweating, and unstable blood pressure and body temperature. In addition, people with familial dysautonomia can have learning disabilities. The average life expectancy for someone with familial dysautonomia is approximately 30 years.
  3. FANCONI ANEMIA TYPE C MUTATION ANALYSIS
    Fanconi Anemia type C is an autosomal recessive condition that is more common among individuals of Ashkenazi Jewish ancestry. The carrier frequency in this population is approximately 1 in 89. Fanconi anemia type C symptoms can vary from individual to individual. Individuals with the condition typically have short stature, significant bone marrow problems, and may be born with heart, kidney, gastrointestinal, spinal, or limb defects. Lifespan may be shortened, as individuals with the condition are at increased risk for leukemia and other cancers.
  4. GAUCHER DISEASE MUTATION ANALYSIS
    Gaucher disease is an autosomal recessive condition that is more common among individuals of Ashkenazi Jewish ancestry. Gaucher disease consists of three different disease variants, which differ in terms of age of onset and severity. The carrier frequency in this population is approximately 1 in 12. Symptoms may include fevers, bone pain and fractures, problems with blood clotting, anemia, seizures, enlargement of the spleen and liver, and may result in a shortened lifespan. The symptoms of Gaucher disease can be treated through replacement of the enzyme that is deficient in affected individuals through regular, lifetime intravenous infusions.
  5. NIEMANN-PICK DISEASE TYPE A MUTATION ANALYSIS
    Niemann-Pick type A is an autosomal recessive condition that is more common among individuals of Ashkenazi Jewish ancestry. The carrier frequency in this population is approximately 1 in 90. Individuals with Niemann-Pick type A have enlargement of the liver and spleen with rapid neurological deterioration, with death typically occurring by age 4.

Other genetic testing that may have been performed on donors:

  1. CHROMOSOME ANALYSIS
    Chromosomes are found in the cells of our bodies, and they are the packages for our genes. Genes contain the genetic information that directs how our bodies will grow, develop and function. Typically, an analysis of human chromosomes (also called a karyotype) reveals a total of 46 chromosomes per cell. A chromosome analysis will only give us information about the number and structure of the chromosomes present. It will not give us information about specific genes. Infrequently, healthy and normal individuals carry chromosome rearrangements that are referred to as balanced translocations. Balanced translocations typically do not cause any health problems for the person with the translocation. However, people with balanced translocations are at increased risk for infertility, miscarriage and more serious chromosome problems in their children. Approximately 1 in 400 individuals in the general population are carriers of a balanced rearrangement of their chromosomes.

  2. HEMOGLOBIN ELECTROPHORESIS
    Hemoglobin electrophoresis is a diagnostic test that can detect many, but not all, clinically significant differences in a person's hemoglobin. This test can identify abnormal hemoglobins such as hemoglobin S and hemoglobin C. Hemoglobin S is the hemoglobin that is found in abnormal amounts in a person who is affected with sickle cell disease.

    Sickle cell disease is an autosomal recessive hemoglobinopathy that is more common among individuals of African ancestry and Mediterranean ancestry. Among individuals of African descent, the carrier frequency for the gene related to sickle cell disease is 1 in 10. Individuals affected with sickle cell disease can have painful episodes of joint and bone pain, and are at increased risk for strokes, infections and organ damage.

Most of our donors have had a chromosome analysis and hemoglobin electrophoresis. Please contact the Genetics Department if you have questions about the genetic testing performed on a specific donor.