Medical genetics
Article Abstract:
Medical genetics uses genetic advances to diagnose and treat disease. Of 3,000 known heritable diseases, only 100 are associated with known genes (small segments of DNA, the material of inheritance). Within 10 to 15 years, the Human Genome Initiative and related research will have identified all 50,000 to 100,000 human genes. The polymerase chain reaction is a procedure that allows segments of DNA to be amplified, or duplicated, hundreds of thousands of times. When this is done, evaluation of the segment can proceed, and may allow diagnosis of such genetically transmitted conditions as sickle cell disease, and certain thalassemias (a genetically transmitted form of anemia). A partial list of genetic diseases is provided. The first qualifying examination for demonstrating competence in DNA-based diagnostics will be given in 1990 by the American Board of Medical Genetics. Ethical issues raised by the situation surrounding the cystic fibrosis gene are discussed; it is possible, given the high rate of failure to detect mutations, for one parent to know that he or she carries the defective gene, while gene segments from the other partner cannot be accurately identified. Genetic testing is controversial for the cystic fibrosis gene, the retinoblastoma gene, Huntington's disease, and adult polycystic kidney disease. In all cases, accurate identification of the defective gene will bring improvements over statistical risk calculation. DNA-based identification, which can be used in paternity determination, identification of missing children, and forensic studies, is powerful; two reports on this topic are anticipated in 1990. One method of prenatal diagnosis, chorionic villus sampling, can analyze genetic material early in pregnancy (at 9 to 11 weeks gestation), but the procedure's safety levels may not be acceptable. It now appears that up to 70 percent of trisomy 21 pregnancies (Down syndrome) can be detected by blood tests. Public opinion about these diagnostic tests, their accuracy, and cost-effectiveness are important issues for the future of medical genetics. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: JAMA, The Journal of the American Medical Association
Subject: Health
ISSN: 0098-7484
Year: 1990
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Medical genetics
Article Abstract:
The great insights into medical genetics that have been attained in recent years have been largely due to the advances in techniques of molecular genetics. As more experience is gained from laboratory studies of DNA, it becomes easier to study small DNA samples and to locate specific genes. As the techniques are simplified, it is becoming possible for more research groups to apply molecular genetics to the diseases they are studying, without the need for an extensive DNA technology laboratory. Likewise, even the traditional genetic research method of assembling the family pedigree to study gene linkage has been improved by the introduction of molecular techniques. The Human Genome Project began in 1990; this 15-year, multibillion dollar project will attempt to determine the DNA sequence for the entire human genome. The first phase will be mapping, in which the location of genes on the chromosomes will be worked out. The ultimate goal, however, is the sequencing of all of the estimated 3.3 billion base pairs of DNA. While some have questioned the wisdom of spending enormous amounts of money and effort on this project, it should also be remembered that enormous amounts of money are already being spent on genetic disorders. For example, the genetic disorder polycystic kidney disease accounts for 10 percent of all end-stage kidney disease, which requires hundreds of millions of dollars for dialysis and kidney transplantation. DNA analysis can identify the carriers of this disease gene, as well as the genes for many other genetic disorders, which are not only devastating for the patient, but enormously costly to society as well. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: JAMA, The Journal of the American Medical Association
Subject: Health
ISSN: 0098-7484
Year: 1991
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Medical genetics
Article Abstract:
Researchers discovered gene defects responsible for many diseases during the 1990s. They included genes involved in maturity-onset diabetes of the young, a premature aging syndrome, Bloom syndrome, and Li-Fraumeni cancer syndrome. Gene mutations that increase the risk of colon, breast and prostate cancer have also been identified. These mutations could be the basis for genetic screening, which is still very controversial. Many neurologic disorders have a genetic component, including fragile X syndrome, Huntington disease, Parkinson's disease and migraine.
Publication Name: JAMA, The Journal of the American Medical Association
Subject: Health
ISSN: 0098-7484
Year: 1997
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