Birth Defects and Inherited Disorders

Written by docteam Friday, 20 August 2010 18:56

Specters of birth defect and inherited disease can throw a pall over the bright expectations of parent to be. The process of genetic counseling, along with new ways of determining whether a fetus is likely to be normal, has taken much of the mystery out of predicting  pregnancy outcomes. Through genetic counseling a couple may be told if an inheritable disease or disorder is likely to be carried to an offspring or if high risk pregnancy may develop.

The medical procedures used for these determinations  include removing a sample of fluid from the pregnant uterus, and examining pelvic structures and the developing fetus by insertion of special medical devices. Fetal abnormalities that may be identified or ruled out through prenatal testing and counseling include sickle cell anemia, Tay- Sachs disease, phenylketonuria (PKU), Down’s syndrome (mongolism, thalassemia, and neural tube defects such as spina bifida.

Genetic counseling can actually start before the couple marries, because knowing that their pairing may result in a child with an inherited disorder can make a difference in the couple’s decision about marriage and childbearing. Some inherited disease  are carried by the mother and passed on almost exclusively to male children. These disorders are known as X-linked recessive disorders and include color blindness, hemophilia, and childhood muscular dystrophy. They are called X-linked recessive because they are carried on the X sex chromosome of the mother.

Other inherited disease disorders, called autosomal recessive (means two copies of an abnormal gene must be present in order for the disease or trait to develop), are inherited only if both parents carry the gene disorder. Even then, the chances are only one in four that each offspring will have the disease. years ago knowing that such a disease existed in the families of two people planning to marry might have been enough to call of the wedding. But today carries tests for these genetic disorder often rule out one or both partners as carriers.