2.1 Biomed

  • Genetics - study of heredity

  • I.E. passing characteristics from parents to off spring

  • Characteristics (categories): height, eye color

  • trait (type): tall, blue

  • Genes: section of DNA that codes for particular characteristic

  • Alleles: diff. form of gene that codes for particular trait

Types of alleles:

  • Dominant: always displayed

  • - Capital letter

  • Recessive: only displayed if dominate is absent

  • - Lower case

  • Genotype: combination of patients alleles

  • Phenotype: physical appearance

combinations

  • Homozygous: Same allele from each parent True -Breed"

  • Heterozygous: diff. allele from parents ("Hybrid")

What?: Both environmental & genetic Factors play a role in the developmental of disease

Single Gene disorder: caused by changes or mutations that occur in the DNA sequence of I gene

  • Resulting in a protein product that can no longer carry out it's normal job

  1. Autosomal dominate \ chromes # 1-22

  2. Autosomal recessive

  3. Sex linked 一X & Y

    • - Huntingtons Disease

    • Carriers (nave I recessive copy of gene) Ex: Cystic Fibrosis

    • Located on X chromosome. Individuals w/ XX may be carriers

      • Duchenne Muscular Dystrophy

Multifactarial Disorders: Caused by comb. of environmental Factors & mutations of multiple genes

  • heart disease

  • Breast cancer

  • Alzheimers

Chromosomal Disorder: problems arise wnen there are missing / extra copies of genes, or breaks, deletions or rejoining of chromosomes

  • Trisomy 21 (down Syndrome)

Mitochondrial Disorders: caused by mutations in non- Chromosomal DNA of mitochondria.

  • passed solely from mother to child.

  • Leber Hereditary Optic Neuropathy was

PCR:

  • Creates a large number of copies of one gene for genetic testing

    1. Target DNA

    2. Denaturation at 94 degrees celsius

    3. Annealing between 40 and 65 degrees celsius

      • primer: identifies the start and end of target sequence (gene)

    4. Extension at 72 degrees celsius

      • Taq Polymerase: build a DNA complement of target sequence using dntps

      • dntps: free floating DNA nucleotides

Thermal Cycler: Machine that regulates time and temperature at each stage of PCR

  • typically runs 30 cycles

  • creates 2 ^n+1 copies of DNA (n = number of cycles)

Parental Testing:

Who: Pregnant woman

How: Through blood tests, ultrasounds, and sometimes kick counts

What: Cystic Fibrosis

Newborn testing:

Who: All Newborns

How: Small sample of blood from heel and testing for disorders

What: Hemoglobin disorders and endocrine disorders

Carrier screening:

Who: People who are considering pregnancy

How: By analyzing a sample of your blood, saliva, or cheek tissue

What: Sickle cell disease and cystic fibrosis

Amninocentesis:

  • Tests amniotic fluid

  • tests for neural tube defect

CVS (Chorionic Villus Sampling):

  • Tests chorionic follicles from placenta

  • Tests for chromosomal abnormalities

Karyotype: A visual representation of an individuals complete set of chromosomes typically arrange in pairs based on size and shape