The other end of the screening spectrum is also transforming. Carrier screening, which tests potential parents for hidden genetic mutations that could affect their children, initially involved testing specific genes in at-risk groups.
Now it is available to almost everyone who can afford it. The companies will offer to test hundreds of genes to help people make informed decisions as they try to become parents. But advanced media verification has its drawbacks. And it's not for everyone.
This is what I discovered earlier this week when I visited the Progress Educational Trust. annual conference in London.
First, a little background. Our cells carry 23 pairs of chromosomes, each containing thousands of genes. The same gene, say the one that codes for eye color, can have different forms or alleles. If the allele dominantyou only need one copy to express this trait. This is the case with the allele responsible for brown eyes.
If the allele recessivethis trait will not appear unless you have two copies. This is the case, for example, with the allele responsible for blue eyes.
The situation gets more serious when we look at genes that may influence a person's risk of disease. The presence of a single recessive gene causing a disease usually does not lead to You any problems. But the genetic disease can appear in children who have inherited the same recessive gene from both parents. The probability that two “carriers” will have a sick child is 25%. And these cases can come as a shock to parents, who typically have no symptoms or family history of the disease.
