Biomed Unit 2-How to Screen What is in Your Genes

Unit 2- How To Screen What is in Your Genes 2.1- Genetic Testing and Screening Vocabulary Genes A discrete unit of hereditary information consisting of a specific nucleotide DNA sequence. Genetic Counselor A specialist dealing with the process of communication concerning the occurrence or risk that a genetic disorder will occur in a family. Genome The complement of an organism's genes. Genetic Diseases Illnesses that originate in the chromosomes and DNA. Genetic Testing The use of methods to determine if someone has a genetic disorder, may develop one, or is a carrier for one. Genotype The genetic makeup of an organism. Phenotype The physical and physiological traits of an organism. Allele One of the 2+ forms of a gene. Single- nucleotide polymorphism One base pair variation in the genome sequence. Taq Polymerase An enzyme taken from a bacteria that is used to copy DNA because it doesn’t break down in high temperatures. Thermal Cycler Used to amplify DNA and RNA samples by PCR, raises and lowers the temperature to denature and anneal the sample allowing more copies to be made. Screening Tests used to monitor the growth of the fetus and check for chromosomal abnormalities. Noninvasive The test has minimal risks or impact on the mother or child. Diagnostic Provides a more definitive answer as to weather or not a child will be born with a particular disorder or condition. Karyotype A display of the chromosome pairs of a cell arranged by size and shape. Carrier Screening Tests if someone has one copy of a defective gene to a recessive disorder but doesn't display traits. Types of Genetic Disorders ● Single Gene ○ Recessive, dominant, sex-linked disorders ○ Caused by changes or mutations that occur in the DNA sequence of a gene ● Multifactorial ○ Caused by a combination of environmental factors and mutations in multiple genes. ● Chromosomal ○ Caused by missing, extra, or broken chromosomes, deletions, or rejoinings. ● Mitochondrial ○ Mitochrondiral DNA only comes from the mother ○ Caused by mutations in non chromosomal DNA of mitochondria. Steps of PCR ● Denaturing ○ double stranded DNA is heated up until the hydrogen bonds break, separating the strands. ● Annealing ○ Enabling DNA primers to attach to template DNA at a specific location. ● Extension ○ The temperature is raised and the new strand of DNA is made by the taq polymerase enzyme. 2.2- Our Genetic Future Vocabulary Gene Therapy The alteration of the genes of a person with a genetic disease. Vectors An agent that carries genetic material and can introduce other genes into another organism. Genome Editing A technique that uses tools in the cell, the DNA and replaces the mutated genes with healthy ones. Dominant Negative Interferes with normal function. Gain of Function An abnormal function begins to work. Improper Regulation There is too much or too little or something in the cell. Ovulation Induction Hormones that stimulate follicle production. Artificial Insemination Insertion of sperm into a woman's cervix or uterus. Donor Conception Donors eggs or sperm are inserted in the patient. In-Vitro Fertilization Gametes are fertilized in a dish in a lab then implanted in the uterus. Intracytoplasmic Sperm Injection Direct insertion of sperm into one or more eggs. Surrogacy A woman carries another woman's child. Gene Therapy ● Gene Therapy Candidates ○ Is the mutation responsible for the condition 1 or more genes? ○ Which gene is involved? ○ What do you know about the biology of the disease? ○ Will adding a normal copy fix the problem? ○ Can the gene be delivered to the affected cells? Gene Silencing ● Turns the gene expression off to prevent formation of protein from the gene. ○ Triple helix forming oligonucleotide gene therapy ■ Delivers single strands of DNA that bind between strands of the mutated genes, preventing it from being transcribed into mRNA. ○ RNA interference ■ Introduces a small piece of RNA, complementary to a piece of the mRNA, which attaches and forms a double helix which is killed by the cell. ○ Ribosome gene therapy ■ Ribosomes targeted to destroy mRNA with a mutated gene.