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Genetic Disease And Fetal: A new vaccine that took eight years to develop has virtually put an end to infant mortality from erythroblastosis fetalis (a blood-destroying disease of the fetus and the newborn). This fatal disease, characterized by hemolytic anemia that Iresults from the destruction of red blood cells, [byjaundice, and by other severe manifestations, ; is caused by incompatibility of fetal and mater-|nal bloods. This incompatibility results when ;the mother has become sensitized against the [_ fetal blood-group antigen, the Rh factor. Be-t cause the mother is immunized to the blood of the fetus, she produces antibodies that pass into the fetal circulation and destroy the fetal > red blood cells.
Spontaneous mutation was still regarded as inevitable in its primary occurrence and in the eventual toll that it exacts in the form of genetic disease and fetal death. Exact knowledge of DNA replication, however, would soon dispel much of the mystery surrounding the mutation process and show how it could be intelligently controlled. A great deal was already known about how radiation damages DNA and intracel-lular repair mechanisms. DNA studies were also providing the basis for warnings about a number of chemical compounds that contaminate the environment and that may play an important role in the deterioration of human genes.
For a specific example of the way in which genetic information contained in a particular gene is expressed in an organism, let us consider the case of the human disease sickle-cell anemia. To understand how this disease comes about, one must first look at the function of hemoglobin, which is the protein in red blood cells that picks up oxygen in the lungs and carries it to the body tissues. |
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