GENETIC MUTATIONS GENE MUTATIONS Change/mistake with individual gene Point Mutation – 1 amino acid is changed Frameshift Mutation – an amino acid is added or deleted

GENETIC MUTATIONS CHROMOSOMAL MUTATIONS Mistakes affect the entire chromosome Deletion: lose part of chromosome Duplication: gain extra parts on a chromosome

GENETIC MUTATIONS Inversion: rearrangement of the chromosome Translocation: genes are rearranged btw 2 different chromosomes

GENETIC MUTATIONS Nondisjunction: chromosomes do NOT separate during meiosis  results in polyploidy (too many chromosomes) Cause of many different genetic diseases Down’s, Klinefelter, Turner’s, Triple X, XYY

DIAGNOSING GENETIC DISEASES GENETIC COUNSELORS Research family history to determine parents’ risk of passing genetic disorders to their children Typically used by couples with family history of genetic disorders

DIAGNOSING GENETIC DISEASES GENETIC TESTING Carrier Recognition – parents can be tested to see if carry genes for genetic disorder (Tay-Sachs, cystic fibrosis, sickle-cell anemia) Fetal Testing – test unborn child for genetic disorders Remove fetal tissue Allow cells to multiply in the lab Magnify & photograph chromosome spread Create a karyotype – map of chromosomes

NORMAL KARYOTYPES MALEFEMALE

DIAGNOSING GENETIC DISEASES Types of Fetal Tests: Amniocentesis (15-20 wks) – remove amniotic fluid from mother Fluid tested for chemical indicators or used create karyotype CVS - Chorionic Villus Sampling (8-10 wks) Remove tissue from placenta – more immediate results Ultrasound – looks for major structural abnormalities Fetoscopy – insert fiber optic scope into uterus to examine fetus for major abnormalities

DNA FINGERPRINTS DNA can be collected from any living tissue (blood, skin, hair, urine, semen, sweat or tears) Gel Electrophoresis DNA sample is inserted into a “gel” An electric current is passed through the gel Shorter strands move farther down the gel as pieces of DNA separate & show up as bands Gel is stained to make the bands more visible Samples are compared to find a match

DNA FINGERPRINTS

Human Genome Project Map all the genes on the 46 human chromosomes Information has led to many advances in the fields of medicine, agriculture, bio-engineering

GE – WHAT IS IT? Removing genes from one organism and inserting them in another

GE – HOW DO THEY DO IT? RESTRICTION ENZYMES Naturally occur in bacteria – used cut up foreign DNA (form of protection) Cut DNA fragments are called “sticky ends” S. ends of DNA fragments can be joined in a lab to produce recombinant DNA (mix of DNA)

GE – WHAT CAN IT DO? PROS Disease resistant crops New vaccines & medications (insulin) Bigger livestock  more meat, milk, wool etc. CONS Unpredictable  technology is new & no guarentee that products free of side affects $$  companies patent genes & demand high prices

GENE THERAPY Replace defective genes w/ normal or functional genes When cells reproduce  normal gene will also be replicated Most suitable for single gene mutations Enzyme deficiencies

SOMATIC CELL THERAPY Somatic cells = body cells Mutated cells removed Corrected gene inserted “New” cells returned Affects only the individual receiving treatment Temporary cure – cells die off

STEM CELL THERAPY Stem cell = basis all future cells Found embryo, chord blood & bone marrow May provide broader, more long-lasting treatment Not currently safe or 100% effective

GERM CELL THERAPY Germ cells = gametes Replace or remove defective genes in sperm/egg cells prior to fertilization Affect future generations Permanent solution Successful in mice & primates Social & Ethical Issues Are humans next? Who should have access to this technology? Are we playing God? If we can fix disorders, what else could we fix? Where do we draw the line – what is too much?