Warm-Up #4 2/10/09 1. Which members of the family above are afflicted with Huntington’s Disease? 2. There are no carriers for Huntington’s Disease- you either have it or you don’t. With this in mind, is Huntington’s disease caused by a dominant or recessive trait? 3. How many children did individuals I-1 and I-2 have? 4. How many girls did II-1 and II-2 have? ** How many have Huntington’s Disease?

Discovering the Human Genome Chapter 11 & 14

EQ: Do genomes only come from humans? Objectives: Identify the types of human chromosomes in a karyotype. Explain how gene maps are made. Identify causes and symptoms of genetic diseases. Describe techniques that detect genetic disorders. Describe the purpose of the Human Genome Project.

Karyotyping of Chromosomes A picture is taken during mitosis to analyze chromosomes. Chromosomes are cut out and arranged in pairs by size. They are numbered by size. Autosomes—22 pairs of chromosomes Sex Chromosome—Pair # 23 (Shown as XX or XY)

Klinefelters Disease Nondisjunction Trisomy Affects Males Genotype-XXY (47) Characteristics show up during puberty. Symptoms: usually tall and usually do not develop 2 nd ary sex characteristics - facial hair, or underarm and Body hair.

Down Syndrome Nondisjunction “ Trisomy 21” Affects over 350,000 people in the US (1 in 800 live births) Symptoms: mental retardation, eyes that slant upward, and heart defects. 3 copies of chromosome 21. In 90% cases, the extra chromosome comes from the mother's egg.

Mom's age Incidence of Down syndrome Mom‘s age Incidence of Down syndrome under 30 less than 1 in in in in in in in in in in in in 12

Turner Syndrome Nondisjunction Monosomy Females have only one X chromosome. (45) (Xo) Affects 60,000 females in the US. 1 in 2000 live births 800 new cases each year. Symptoms: short stature, no ovarian development (No 2 nd ary sex characteristics), webbed neck, low hairline in the back of the head, and a shield-like chest. Sterile In 75 to 80 percent of cases, missing the father’s X.

Sickle-cell anemia autosomal recessive (incomplete dominance) chromosome 11 9% of US blacks are heterozygous, while 0.2% are homozygous recessive. Causes a single amino acid substitution in hemoglobin changing its shape. Carries less oxygen. Brittle cells. hemoglobin Cells break when passing through vessels causing blockage, tissue damage, and great pain. Carriers and those with disease can not get malaria – protist can not live in sickle cells.

Cystic Fibrosis (CF) autosomal recessive chromosome 7 Symptoms: Production of mucus clogging the airways of the lungs and the ducts of the pancreas and other secretory glands. Bacteria grows causing infectionsmucuspancreas Digestive enzyme deficiency prevents food from being digested and absorbed CF is the most common genetic disease in Caucasian.

Hemophilia sex-linked recessive Results in the absence of certain blood-clotting factors, usually Factor VII. Hemophiliacs suffer from an inability to clot their blood. “Bleeder’s Disease” Mostly males but changing.

Detection of Genetic Diseases Genetic Counselors Provide information and support to families who have members with birth defects or genetic disorders. Family History Assessment Identify families with inheritable conditions.

Detection cont. Screening - consists of analyzing a blood sample Prenatal diagnostic testing involves testing the fetus before birth Include: Ultrasonography Chorionic villus sampling - doctor inserts a thin flexible tube (catheter) through the vagina and the cervix into the placenta removing a small sample of the chorionic villi (part of the placenta) Preformed weeks. Amniocentesis - sample of the fluid that surrounds the fetus (amniotic fluid) is removed. Performed at 14 weeks Percutaneous umbilical blood sampling – using a needle sample of the fetus's blood is withdrawn and analyzed Genetic Engineering Techniques DNA Testing

Fixing Genetic Problems Gene Therapy An absent or faulty gene is replaced by a normal working gene. This enables the body to make the correct protein it needs Normal hemoglobin gene Bone marrow cell Chromosomes Genetically engineered virus Nucleus Bone marrow

Human Genome Project A genome is all the DNA in an organism identify all 20,000-25,000 genes in human DNA, Recording the order of As, Ts, Cs, and Gs in human DNA in each chromosome.

Human Genome Project Project goalsgoals Formally began in 1990, the U.S. Human Genome Project was a 13-year effort completed in determine the sequences of the 3 billion chemical base pairs of DNA, address the ethical, legal, and social issues (ELSI) that may arise from the project.

Ethics: Fairness in the use of genetic information by insurers, employers, courts, schools, adoption agencies, and the military, among others. Privacy and confidentiality of genetic information. How does it get used? Who owns and controls genetic information? Can your genetic makeup be held against you?