Recessive Genes and Birth Defects – Understanding the Chemistry

Biology has proven that the genetic makeup of a child is in large part determined by the genetic makeup of its parents. Thus, there mix of dominant and recessive genes plays a huge role in how a child will look, develop, and which ailments it may be born with. While a dominant gene simply requires for one of the parents to carry it, a recessive gene requires that each parent be a carrier in order to enable the child to have a chance of developing the trait. Thus, if the gene for the development of the brown eye color is a dominant gene, and the gene for the development of the blue eye color is a recessive gene, then a child will most likely have brown eyes if one parent carries the dominant gene, but may develop blue eyes instead if both parents carry the recessive gene that determines this development.

The same may be said of the relationship between recessive genes and birth defects. There are several diseases which may appear in a child’s genetic makeup if both of its parents carry the recessive gene that specifies the development of the disease. It is important to note that even the presence of two recessive carriers does not automatically lead to the development of the birth defect, but instead will most likely give a child a one in four chance of either developing or being unaffected by the hereditary condition, while it gives the child a two in four chance to remain physically unaffected but to nonetheless inherit the gene and become a carrier of the disease.

Birth defects, also known as genetic diseases, are cystic fibrosis, congenital adrenal hyperplasia, Tay-Sachs disease, rotor syndrome and albinism, as well as a host of other conditions. While understanding the chemistry can go a long ways to making an educated decision what a child’s odds of being born with a certain hereditary disease may be, it is important to understand that even with the best of scientific results, the health or lack thereof of a yet to be conceived child is still a lot of guess work. Considering the odds given earlier with respect to recessive genes, prospective parents will have to think long and hard whether to deny themselves the opportunity to experience parenthood or perhaps if it is truly in the best interest of everyone involved if the risks of conception were not taken.

Some prospective parents have found that utilizing in vitro fertilization offers the benefits of having the embryos tested for the presence of genetic makers that indicate the heightened potential for certain birth defects, yet in some cases this presents an ethical dilemma to the parents when it comes to the destruction of the created embryos. Other parents to be seek to forego the heartache of such ethical decisions and opt for egg or sperm donation from an individual who has been tested and is found to not be a carrier of the recessive gene, thus lessening the child’s overall odds of contracting a hereditary disease or birth defect.