People who seek genetic testing are usually searching for something specific. The most common goals are to establish familial relationships or to search for the genetic markers of a disease. In such situations, whole families often have the testing done and compare results, and it can be puzzling when the results differ from one family member to another. To understand genetic evaluation results, it’s first necessary to comprehend just a bit of genetics.
Twenty-two of the pairs, which are sometimes called autosomes, look the same in women and men.
The sex chromosome from the mother is obviously an X. The mother has a pair of X chromosomes, and her contribution to the child will be an X chromosome no matter which one is awarded. This is why doctors say that the sex of the child is determined by the father. If he provides an X chromosome, then the child’s 23rd chromosome is going to be an X-X pair and the child will be a girl. If he provides a Y, the child will have an X-Y pair for the sex chromosome and is going to be a boy.
Another chromosomes may look alike, but on a molecular scale they are not. As a child’s sex is determined by the particular sex chromosome he or she receives from the father, other traits are dependent on the specific genes passed down on every chromosome. Siblings may have quite similar external appearances, but the particular gene combinations on the chromosomes can lead to very different evaluation results.
Sometimes a single gene is sufficient to cause expression of a particular trait or illness. When this is true, the inheritance is thought to be autosomal dominant. Sometimes the identical gene must be inherited from both the mother and the father for saying to happen. When this happens, the inheritance is believed to be autosomal recessive.
The situation is further complicated in that not all genes really express. Some genes are just markers or switches that turn other genes on or off. Siblings might possibly receive a receptor, or a set of genes, for an expression that is either autosomal dominant or recessive, but not both receive the genetic change or switches which turn the gene on.
With everybody made up of the plethora of gene combinations, not only from their parents, but also grand-parents, great grand-parents and so-forth back family generations, it’s easy to see why same family members genetic evaluations may lead to different results. This is the reason it’s a fantastic idea to get several family members tested across different generations so that you can discover a stronger link to your family’s ancestry history. It is also very exciting to uncover new and terrific things about yourself and your family relations to it is past.