Any prospective donor who is found to be a carrier for a genetic condition that we screen for is not accepted into the donor program. Below is the current list and descriptions of genetic screening tests performed on donors. IDANT can also test donors for certain genetic conditions at the request of clients who know that they are carriers for, or affected with a specific genetic condition. Please contact us for more information.
Canavan disease is a rare, inherited, neurological disorder characterized by spongy degeneration of the brain, in which the white matter is replaced by microscopic fluid-filled spaces. It is caused by a deficiency of an enzyme called aspartoacylase. Symptoms of Canavan disease, which appear in early infancy and progress rapidly, may include mental retardation, loss of previously acquired motor skills, feeding difficulties, abnormal muscle tone, poor head control, and megalocephaly (abnormally enlarged head). Death usually occurs by age four.
All donors of Jewish ancestry are tested for the mutations that cause Canavan disease.
Cystic fibrosis (CF)
CF is an inherited disease caused by an abnormal protein that does not allow the normal passage of salt into and out of certain cells, including those that line the lungs and pancreas. As a result, these cells produce thick, sticky mucus and other secretions. The mucus clogs the lungs, causing breathing problems. Affected individuals also have frequent lung infections, which eventually damage the lungs and contribute to early death. The thickened digestive fluids made by the pancreas are prevented from reaching the small intestine, where they are needed to digest food.
To inherit CF, a child must receive two CF genes, one from each parent who "carries" a CF gene. A carrier has one normal gene and one abnormal gene in the pair, and is as healthy as a non-carrier. When both parents carry an abnormal CF gene, there is a 25% chance that the child will have CF.
While all racial groups are affected, the disease is most common in Caucasian individuals. If indicated in their family / genetic history, donors are tested for the CF gene.
Sickle cell disease
Sickle cell disease is an inherited disease of red blood cells which is more common among individuals of African ancestry. Sickle cell disease the hemoglobin in red blood cells, which causes attacks of pain, damage to vital organs, risk of serious infections and can lead to early death. The disease occurs when a person inherits one sickle cell gene from each parent or a combination of one sickle cell gene plus one of several other abnormal hemoglobin genes. All donors with African ancestry are screened for the sickle cell trait.
Tay-Sachs disease is a fatal inherited disease of the central nervous system that begins in infancy, usually within 4 to 6 months of age, in which an enzyme deficiency leads to the accumulation of gangliosides in the brain and nerve tissue, resulting in mental retardation, convulsions, blindness, and, and typically results in death by age 5. Babies with Tay-Sachs lack the protein enzyme called hexosaminidase A (hex A) necessary for breaking down certain fatty substances in brain and nerve cells. These substances build up and gradually destroy brain and nerve cells, until the entire central nervous system cease to function.
Tay-Sachs carriers have one normal gene for hex A and one Tay-Sachs gene. The carrier does not have the illness and leads a normal, healthy and full life. However, when two carriers become parents: There is a 25% chance that any child they have will inherit a Tay-Sachs gene from each parent and have the disease. There is a 25% chance that the child will inherit the normal gene from each parent and be completely free of the disease and the Tay-Sachs gene. There is a 50% chance that the child will inherit one of each kind of gene and be a carrier like the parents and free of disease. If only one parent is a carrier, none of their children can have the disease, but each child has a 50-50 chance of inheriting the Tay-Sachs gene and being a carrier.
The Tay-Sachs carrier screen is performed on donors of Jewish and French-Canadian ancestry.
A thalassemia carrier screen is performed on donors of Mediterranean origin using a diagnostic test procedure called hemoglobin electrophoresis. Hemoglobin is the protein in our red blood cells that carries oxygen and nutrients to all parts of the body.
Thalassemia is a genetic blood disorders that affect a person's ability to produce the hemoglobin molecule. Thalassemia is an inherited disease, which means it is passed on from parents to their child through their genes. Both parents must have the thalassemia trait in order to pass the disease on to their child, but it only takes one parent to pass the trait onto his/her child. The thalassemia trait will never develop into disease. Thalassemia trait can be passed on for many generations without being detected before a child is born with disease.