- What are the genetic disease tests performed on the donors?
See the list of genetic tests performed on our donors.
- What kinds of genetic issues are screened for in the donor’s health history?
All donors will have a three-generation family history reviewed by a geneticist. The family history will present information on illnesses and birth defects noted in the individual family members, causes of death, history of miscarriage or reproductive failure, and any known hereditary disorder. Any donor at an increased risk for a genetic or hereditary disorder above that expected in the general population, will be excluded.
Examples of disorders that would exclude a donor include alcoholism in a first degree relative, a sibling with spina bifida, a donor with a medical condition such as a heart defect or diabetes, and mental illness or mental retardation in a first degree relative.
- Does the normal chromosome analysis on the donor tell me he has no genetic problems?
A chromosome study looks at the whole structure of the chromosome, detecting changes in chromosome structure. It does not look at the level of the genes, which make up the chromosomes like beads on a string. Thousands of genes make up every chromosome. A normal chromosome analysis tells us that no obvious chromosomal defects were found but does not tell us that the genes that make up those chromosomes are indeed normal. Individuals with abnormal chromosome structure (chromosomal rearrangements) are at increased risk for reproductive failure and having children with significant birth defects. They would be excluded from the donor register.
- Do you look at the genes of the donor for abnormalities?
Yes, for a limited number of disorders. We do not do a general test that looks at all genes. See the list of genetic diseases tested. Not all genetic diseases known are tested, rather those that are common enough to cause concern, that involve a serious medical condition and that have a readily available genetic test may be selected for testing by our medical director in consultation with our medical advisory board. As gene research progresses, we are constantly evaluating this list of tests on our donors.
- If my family history is normal and I am healthy, then what is the chance, if I use a Fairfax Cryobank donor, to have a child with a birth defect?
We cannot guarantee that the risk is zero. We know that any healthy couple conceiving a pregnancy has a 3-4% chance of having a child with a birth defect. Family history, good prenatal health, folic acid supplementation prior to and during pregnancy (reducing the risk of neural tube defects), and the age of the mother are all factors that affect the risk for birth defects. Screening tests during pregnancy may be able to offer you important information on the health of your unborn baby.
Please discuss any concerns with your physician.
- I am a carrier of a genetic disease and would like to have a donor tested before I use him. Do you provide this service?
Yes, under certain circumstances. We are eager to help you find a donor who is negative for the disease in question so you can increase your chance of having a healthy child. Please contact us and ask to speak to the genetic counselor who can work with you. Typically we request you select several donors from our list so we can see which one might be available for testing. Once the cost of the testing is paid by the client, we will proceed to coordinate what is required.
- Is autism genetic?
Autism is a behaviorally defined pervasive developmental disorder that affects how a child functions in several areas, including speech, social skills and behavior. Children who have problems in these areas are sometimes said to have an autistic spectrum disorder (ASD) because the severity of symptoms varies greatly.
Autism affects about 1 in 88 children in the United States. More children than ever are being diagnosed with autism. The rates of diagnosis of ASD are about 10 times higher than in the 1980s, though much or all of this increase may be due to improved awareness and changes in how autism is diagnosed.
Genetically, it is clear that the ASD represent a number of different disorders which have some overlap in features. Genetic inheritance has been strongly suggested by studies of twins and families with multiple affected children. Overall, it is believed that there are many genes involved in ASD along with possible environmental or immunologic triggers.Advanced paternal age (over the age of 45) has also been implicated. A number of studies have been performed to estimate the recurrence risk in families who already have a child with ASD. Older studies showed that the recurrence when there was a child in the family with autism spectrum disorder could be much higher depending on the number of affected siblings and the gender of the current fetus. Overall a recurrence risk of 18.7% for full siblings of an affected child were reported. For half siblings the risk can only be estimated, and may be on the order of 4-8%. At the current time, there are no prenatal tests to detect children who will be affected with ASD.
- If I select a donor with a certain physical feature, what is the chance his offspring would inherit it?
The answer is not clear. A child’s appearance will often resemble some features of both parents but it is not predictable which features those will be.
- I would like my baby to have a certain eye color, can I select a donor that makes that more likely?
Yes you can select a donor to make it more likely, but it is not guaranteed. Eye color does not follow a strict pattern of inheritance. A general rule is that the color brown is dominant while the color blue is recessive. It appears that two genes determine eye color. One gene comes from each parent. A parent can have brown eyes and have one brown gene and one blue gene (brown is dominant and ‘masks’ the blue gene) or two brown genes. A person with blue eyes often has two blue genes. We don’t always know what the genes are just by looking at the eye color in an individual. A person with hazel or green eyes may be any combination of brown and blue genes. Also, eye color can also change as a child grows older as some with light colors become darker with age. It is not uncommon to see a blue eyed child when both parent have brown eyes. It is less common to see a dark eyed child from parents who both have blue eyes but it is possible.