Treating Genetic Disease

Physicians can treat genetic diseases in several ways. For many diseases they can treat just the symptoms. For example, an individual with the genetic disease phenylketonuria (PKU) lacks an enzyme that converts the amino acid phenylalanine into the amino acid tyrosine. Phenylalanine builds up in the body and causes severe mental retardation. Physicians prescribe strict food regimens for phenylketonuria (PKU) patients to eliminate the amino acid phenylalanine from their diets. PKU can be detected by means of a blood test administered to infants during the first few days of life.

figure 12-15

Jeff Pinard discusses with a colleague the results of his DNA analyses of cystic fibrosis.

figure 12-15

Jeff Pinard discusses with a colleague the results of his DNA analyses of cystic fibrosis.

For cystic fibrosis patients, physicians prescribe 45-minute-long sessions of pounding on the back and chest to dislodge sticky mucus.

For some diseases, physicians can implement symptom-prevention measures. For example, a physician might prescribe insulin injections to patients with diabetes. For patients with hemophilia, a doctor might prescribe injections of a missing blood-clotting protein. Physicians can even do some types of surgery to correct genetic defects in a fetus before birth.

Gene Therapy

Another level of treatment currently in development involves replacing the defective gene. This type of therapy, called gene therapy, is a technique that places a healthy copy of a gene into the cells of a person whose copy of the gene is defective. Gene therapy relies on knowing gene sequences like the one Pinard is viewing in Figure 12-15. Medical researchers place a functional allele of the gene, such as the CFTR gene, into the DNA of a virus. They then introduce the modified virus into a patient's lungs where the virus infects the cells and brings along the functional gene. This improves the patient's symptoms, but only until the infected cells slough off. Then the patient must undergo the procedure again. Researchers are working to increase the effectiveness of gene therapy.

Gene therapy, in which only body cells are altered, is called somatic cell gene therapy. This contrasts with germ cell gene therapy, the attempt to alter eggs or sperm. Bioethicists, who study ethical issues in biological research, generally view somatic cell gene therapy as an extension of normal medicine to improve patients' health. Germ cell gene therapy, however, poses more risks and ethical issues because future generations could be affected in unpredictable ways.

Supplements For Diabetics

Supplements For Diabetics

All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.

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