Genetics In Primary Care


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Genetics In Primary Care

  1. 2. Catch the Wave!
  2. 3. Developments in Genetics <ul><li>Steve Meixel, MD </li></ul><ul><li>Department of Family Medicine OU-Tulsa </li></ul>
  3. 4. Genetics in Primary Care (GPC) A Faculty Development Initiative The GPC is a 3 year contract funded by: Maternal and Child Health Bureau Bureau of Health Professions H.R.S.A. Co-funded by the Nat’l Human Genome Proj. Research Institute Agency for Healthcare Research and Quality N.I.H.
  4. 5. Our lives are being approached by waves of new genetic information and technology.
  5. 6. These waves are getting bigger and making more of an impact on our lives. Just consider the rapid developments in genetics over its brief history…
  6. 7. Genetics History <ul><li> 2000 Draft of Entire Human Genome </li></ul><ul><li> 1999 1 st Human Chromosome(22) sequenced (OU helped) </li></ul><ul><li> Drug Firms Consortium </li></ul><ul><li> 1997 “Dolly” (a sheep) cloned </li></ul><ul><li> 1995 1 st Non-viral Genome sequenced (H. Flu.) </li></ul><ul><li> 1990 Human Genome Project begins </li></ul><ul><li> 1974 Restriction Enzymes cut up DNA to sequence genes </li></ul><ul><li> 1953 Watson and Crick define structure for DNA </li></ul><ul><li>1902 Garrod: Alkaptonuria (1 st case of recessive inheritance) = “Inborn error of metabolism” as a cause of disease </li></ul><ul><li>1865 Mendel describes laws of genetics (from pea plants) </li></ul>
  7. 8. The “Genetic Wave” is continually building. Consider these facts, developments, and comments…
  8. 9. Genetics Factoids <ul><li>Human Genome: 3,000,000,000 base pairs (200 vol. of a 1,000 p. telephone book) </li></ul><ul><li>80,000 Genes: 1,000-500,000+ bases/gene </li></ul><ul><li>1665 Disease Genes found (so far): e.g.familial breast and colon cancer, Alzheimer’s disease, hemochromatosis, neurofibromatosis….. </li></ul>
  9. 10. <ul><li>GENOME = LIBRARY </li></ul><ul><li>CHROMOSOME = BOOK </li></ul><ul><li>BAND = CHAPTER </li></ul><ul><li>GENE = SENTENCE </li></ul><ul><li>BASE PAIR = LETTER </li></ul>An Analogy
  10. 12. Genetics Factoids <ul><li>Human Genome: 3,000,000,000 base pairs (200 vol. of a 1,000 p. telephone book) </li></ul><ul><li>80,000 Genes: 1,000-500,000+ bases/gene </li></ul><ul><li>1665 Disease Genes found (so far): e.g.familial breast and colon cancer, Alzheimer’s disease, hemochromatosis, neurofibromatosis….. </li></ul>
  11. 13. Gene vs. Chromosome <ul><li>There are thousands of genes on Each chromosome. </li></ul><ul><li>Each gene has a different function. </li></ul><ul><ul><li>There is no one “theme” for each chromosome. </li></ul></ul>
  12. 15. Karyotype- normal male
  13. 16. Chromosome 22 <ul><li>1st chromosome to be decoded (12/99) </li></ul><ul><li>33,000,000 base pairs (>900 genes) </li></ul><ul><li>Involved with: Immune system, cancer, mental retardation, heart disease. </li></ul><ul><li>“ To see the entire sequence of a human chromosome for the first time is like seeing an ocean liner emerge out of the fog, when all you’ve seen before were rowboats.” </li></ul><ul><li>F. Collins (Dir. Of National Human Genome Research Institute of NIH) </li></ul>
  14. 17. Biotechnology <ul><li>The manipulation of biologic matter, such as DNA, for commercial uses. </li></ul><ul><li>“ We are only on the threshold of discovery, at about the same stage that computer technology developers were in the 1950s. But the potential of biotechnology is almost unimaginable.” Richard W. Oliver </li></ul>
  15. 18. Biotechnology Projects <ul><li>Bacteria that “gobble up” pollutants. </li></ul><ul><li>Soil microorganisms that make a biodegradable plastic. </li></ul><ul><li>“ Biosilk”: </li></ul><ul><ul><li>genetically altered spider web </li></ul></ul><ul><ul><li>strongest fiber known (> steel) </li></ul></ul><ul><li>Glue from barnacles (world’s strongest adhesive). </li></ul><ul><li>“ Industrial Tree” grows 100 ft in one year. </li></ul>
  16. 19. Biotechnology
  17. 20. As the waves of genetics grow their impact on our lives gets larger. For example…
  18. 21. National Plant Genome Project <ul><li>Crops resistant to: -disease -insects -drought </li></ul><ul><li>Improve harvest yields </li></ul><ul><li>Extend growing season </li></ul><ul><li>Pesticide free foods </li></ul>
  19. 22. Medical Applications <ul><li>Cloning of organs </li></ul><ul><li>Gene therapy: </li></ul><ul><ul><li>Replace defective gene with normal ones </li></ul></ul><ul><ul><li>Add a gene that suppresses tumor growth </li></ul></ul><ul><li>No more misattributed paternity or “mistaken identity” </li></ul><ul><li>Know risk for disease (alter lifestyle ) </li></ul>
  20. 23. Case #1 <ul><li>Caroline: 20 year old who just found out she is pregnant. The man she suspects is the father was killed in an automobile accident. He was cremated at the request of his parents. He had social security benefits which may be used to support this child if paternity is confirmed. </li></ul>
  21. 24. Case #1 <ul><li>Is it possible to establish paternity in this case without any sample from the father? </li></ul><ul><ul><ul><ul><ul><li>Yes—Family studies </li></ul></ul></ul></ul></ul>
  22. 25. S GF X C X GM M R Parentage testing: reconstruction of a deceased alleged father’s DNA profile by testing his parents S = size GF = alleged father’s father GM = alleged father’s mother C = child M = mother R = control DNA X = mixed DNA, child with GF, child with GM = Paternal contribution = Maternal contribution
  23. 27. SNPs: Single Nucleotide Polymorphisms <ul><li>Minute variations that determine how one person’s DNA differs from another’s </li></ul><ul><li>3,000,000 SNPs in human genome </li></ul><ul><li>Help identify predisposition to disease </li></ul><ul><li>Help identify response to drugs </li></ul>
  24. 28. Pharmacogenomics <ul><li>How a person’s genetic inheritance affects the body’s response to drugs. </li></ul><ul><li>E.g. Iceland Study: test individual genetic profiles against panels of drugs: </li></ul><ul><ul><li>Choose drug with greatest benefit </li></ul></ul><ul><ul><li>Avoid side effects - </li></ul></ul><ul><ul><li>No trial-and-error </li></ul></ul>
  25. 29. As our knowledge of genetics grows so does its effect on our lives. But is the use of this knowledge all good?
  26. 30. Ethical, Legal and Social Implications <ul><li>Genetic facts and risks about a patient extend to family members. </li></ul><ul><li>Insurance coverage could be jeopardized. </li></ul><ul><li>Employers may want genetic information before hiring. </li></ul>
  27. 31. Stem Cell Research <ul><li>“ Kerry rips Bush on stem cell order.” </li></ul><ul><ul><ul><li>Tulsa World 8/8/04 </li></ul></ul></ul><ul><ul><ul><li>Maddox’s Milestone: </li></ul></ul></ul><ul><ul><ul><li>Cubs pitcher registers 300 th win. </li></ul></ul></ul>
  28. 32. <ul><li>Our bodies are made of more than 200 cell types. But a skin cell cannot become a liver cell. </li></ul><ul><li>Stem cells are the blank slate cells of the body. They have the ability to divide & become any of the 200 different types of cells. </li></ul>
  29. 33. <ul><li>The fertilized egg (zygote) repeatedly divides, and in about 5 days, there is a hollow ball of cells called a blastocyst. </li></ul><ul><li>The blastocyst is smaller than a grain of sand & contains 2 different types of cells, the trophoblast & an inner mass of cells which are the embryonic stem cells . </li></ul>
  30. 34. <ul><li>Embryonic stem cells are in the developing embryo for just a couple of weeks after fertilization. Scientists have been able to isolate these cells & keep them growing in the lab. </li></ul><ul><li>Embryonic stem cells can divide indefinitely. Scientists are just learning how to control the cells into becoming specific types of cells like nerve cells or heart muscle cells. </li></ul>
  31. 35. <ul><li>Adult stem cells are descendents of embryonic stem cells, & different types have been found in different tissues, such as skin, fat, breast, blood, lung and brain. These types of stem cells stay in the body for decades. </li></ul><ul><li>The blood stem cells can divide & make more blood stem cells as well as the different types of blood cells like red, white and platelets. Recently scientists found that some adult stem cells may form other tissue types . </li></ul>
  32. 36. <ul><li>Stem cells have lots of possibilities. </li></ul><ul><li>If we learn how to change stem cells into healthy heart muscles cells, can they be used to treat some types of heart diseases? </li></ul>
  33. 37. <ul><li>On Aug. 9, 2001, President Bush decided that federal funds can be used to support stem cell research. However, it is limited to work on the approximately 60 cell lines that were developed before the announcement. </li></ul><ul><li>Currently there is much debate about the limits this announcement places on research in the U.S. </li></ul>
  34. 38. The “Genetic Wave” is building. We can let it pass us by, be overwhelmed by it, or benefit from its energy like a surfer.
  35. 39. Let’s go surfing!
  36. 40. http:// genetics/homepage.htm
  37. 45. The end … (or should I say…The beginning?) Thank you !
  38. 47. <ul><li>Given the right environment, embryonic stem cells can become any one of many different types of tissue. Recently Dr. George Daley & his team of researchers at the Whitehead Institute found a way to transform those cells into egg-like cells. </li></ul><ul><li>Using genetic engineering, Dr. Daley’s team caused embryonic stem cells from mice to grow into structures that resembled early embryos. In these structures, the researchers found & isolated the egg & sperm cells that combine to create embryos. </li></ul><ul><li>The team them allowed the egg cells to grow & develop into cells that resembled natural egg cells. The next step for the researchers involves experiments to determine whether the egg-like cells have exactly the same biological properties as natural produced egg cells. </li></ul>
  39. 48. <ul><li>A fertilized egg cell is immortal; in other words, it can give rise to countless generations. Therefore, the Daley team’s technology could provide an endless supply of cells & tissues. </li></ul><ul><li>-Dec. 2003. </li></ul><ul><li>The following (all text) is by: </li></ul>
  40. 49. SCREEN for Familial Disease (The PPV of this set of questions is not known ) <ul><li>SC=Some Concerns “Do you have Some (any) Concerns about diseases or conditions that seem to run in the family?” </li></ul><ul><li>R=Reproduction “Have there been any problems with pregnancy, infertility or birth defects in your family?” </li></ul><ul><li>E=Early Disease, Death or Disability “Have any members of your family died or become sick at an early age?” or “has there been any early death, disease or disablility in your family?” </li></ul><ul><li>E=Ethnicity “Certain diseases that run in families are more common in certain ethnic groups…How would you describe your ethnicity”, or “Where were your grandparents born? </li></ul><ul><li>N=Non-Genetic “Are there any other risk factors or non-medical conditions that run in your family?” </li></ul>