2.1 and 2.2 MI

  • This unit focuses on the various strategies and technologies used to prevent, diagnose, and treat medical conditions, emphasizing the importance of interdisciplinary collaboration in healthcare.

  • Key areas of exploration include genetic testing, immunotherapy, and the use of advanced imaging techniques to enhance patient outcomes.

  • Furthermore, we will examine case studies that illustrate the successful application of these interventions in real-world scenarios.

Single gene:

  • Single Gene Disorders are basically mutations that happen in the DNA sequence of one of the genes.

    • Recessive

    • Dominat

    • Sex-linked

Multifactorial:

  • Typically a result of environmental factors combined along with multiple mutated genes.

Chromosomal:

  • The 46 chromosomes present in the human body each carry genetic information. When there is extra copying and mutating, problems occur, and a karyotype can help determine the damage done.

Mitochondrial:

  • A rare disease that is caused by a mutation on the chromosomal DNA of the mitochondria. It is always passed down from mother to child.

PCR Basics

  • How many base pairs are there in the human genome?

    • 3 billion base pairs.

  • What is PCR? What does it do?

    • It stands for polymerase chain reaction. It basically allows researchers to make millions of copies of a specific DNA.

  • What are some of the advantages of PCR? Name 1 and explain.

    • PCR only takes about two hours, and it makes it so that researchers don’t need bacteria to amplify the DNA.

  • What is unique about the design of PCR tubes?

    • They are specifically designed to allow the heat to distribute within the thermal cycler.

  • What is the function of a “primer?”

    • Primers act as a starting point for DNA to synthesize a new strand.

  • What does DNA Polymerase do?

    • DNA polymerase forms the new copies of DNA through replication.

  • In Cycle 1 at 95 Degrees Celsius, what happens to the DNA?

    • PCR denatures the target DNA, separating it into single strands.

  • In Cycle 1 at 50 Degrees Celsius, what anneals (attaches) to the DNA strands?

    • The lowered temperature allows the primers to anneal to their complementary sequences. This amplifies the DNA region.

  • In Cycle 1 at 72 Degrees Celsius, what is activated and what is added to the DNA strands?

    • Taq polymerase attaches to the DNA strands and this allows it to extend a new DNA strand.

  • What are the end products of Cycles 2 and Cycles 3?

    • Cycle 2 makes a leading double-stranded DNA sequence, and Cycle 3 is the subsequent cycle with increased target DNA.

Label the processes of DNA replication shown in the picture.

  • Denature

  • Anneal

  • Extend

2.1/2.2 Vocab Words part 1

  • Amniocentesis

  • Anneal

  • carrier screening

  • chorionic villus sampling

  • denaturation

  • Gene

  • genetic counselor

  • Genetic testing

  • Genome

  • Genotype

  • Karyotype

  • newborn screening

  • PCR

  • phenotype

Part 2

  • cloning

  • gene therapy

  • in-vitro fertilization

  • preimplantation genetic diagnosis

  • Primer

  • restriction enzyme

  • sex selection

  • single nucleotide polymorphism

  • supernatant

  • Taq polymerase

  • Thermal cycler

  • Ultrasonography

  • vector

2.2.2. Reproductive Technology

Reproductive Technologies

In Vitro Fertilization (IVF)

  • Sources:

    • IVF Canada

  • When it was developed: 1978

  • Who developed it: Sir Robert Edwards and Dr. Patrick Steptoe

  • Cost: A full round can range from 12k to 24k

  • What it is: In Vitro Fertilization is described as a fertilization method that is used in cases of unfortunate infertility.

  • How it’s done: In a lab dish, sperm is taken and injected into an egg, then placed inside of the woman’s uterus.

  • Why it is used: IVF is often used to achieve conceiving, usually most couples who seek this method are unable to have children due to infertility complications.

Preimplantation Genetic Diagnosis (PGP)

  • Sources: Semantic Scholar

  • When it was developed: 1989

  • Who developed it: Alan Handyside

  • Cost: Ranges between 6k to 12k

  • What it is: A well-developed lab procedure that looks at embryos for genetic conditions before they are implanted in the uterus.

  • How it’s done: IVF is used to put the egg and sperm together, then cells are analyzed and the embryo is taken to be transferred.

  • Why it is used: It’s often used in cases where a couple could be at risk of passing on a genetic Mendelian disease.

Sperm Sorting

  • Sources: ansci.wisc.edu

  • When it was developed: Officially in the 1990s.

  • Who developed it: Ronald Erricson

  • Cost: 1k to 4k per cycle

  • What it is: It’s basically a procedure to allow couples to choose between Y and X chromosomes for their baby.

  • How it’s done: Selective DNA is taken and separated by cell based on chromosomes.

  • Why it is used: To allow couples to choose the gender of their child.

Types of Genetic Disorders

  • Single Gene Disorder: Caused by changes or mutations in the DNA sequences of one gene, resulting in the production of a non-functional protein.

  • Multifactorial Disorders: Caused by a combination of environmental factors and mutations in multiple genes, resulting in many of the most common chronic illnesses.

  • Chromosomal Disorders: Caused when there are missing or extra copies of genes, or breaks, deletions, or rejoining of chromosomes.

  • Mitochondrial Disorders: Caused by mutations in non-chromosomal DNA, which is passed from mother to child.

Purpose of PCR

  • Takes a small part of DNA or RNA and compliments them in order to create thousands of copies of the person's DNA. Cloning sequences of DNA. Change copies from a small sample.

Key Components in PCR

  • Taq Polymerase: A thermostable enzyme used to extend the DNA.

  • Primers: Designed to correspond to the start and end of the target DNA being amplified.

  • dNTPs: Free Deoxyribonucleotides needed for extension.

  • Buffer: A solution used to incubate the reaction components.

Examining DNA

  • Isolating DNA: Extraction of cells.

  • Amplifying DNA: Polymerizing chain reaction.

  • Restriction Analysis: Recognition of SNPs and cutting of DNA.

  • Gel Electrophoresis: Separation of DNA fragments based on molecular weight.

Steps of PCR

  • Denature

  • Anneal

  • Extend

Amniocentesis

  • Inject a large needle through the abdomen and into the uterus, removing amniotic fluid that contains cells for genetic testing.

  • Risks of Amniocentesis:

    • Miscarriage

    • Leaking amniotic fluid

    • Infections

    • Preterm labor

    • Rh sensitization

  • Time performed: 14 weeks of pregnancy (15-20 weeks).

Chorionic Villus Sampling (CVS)

  • Chorionic villus cells are removed from the placenta by inserting a needle vaginally and directing it to the placenta to use a small sample for testing.

  • Risks of CVS:

    • Infections

    • Miscarriage

    • Bleeding/Cramping

    • Fetal Limb deformities

    • Rh sensitization

  • Time performed: Can be performed around 10-12 weeks.

Ultrasound

  • Used sound waves to develop ultrasound images of what's going on inside the body.

  • 3 things doctors/nurses determine using ultrasound:

    • Fetal heartbeat

    • Number of babies present

    • Study and analyze the placenta and amniotic fluid levels.

Positive behaviors during pregnancy for proper prenatal care

  • Consume enough folate (folic acid).

  • Take prenatal vitamins.

  • Maintain healthy eating habits (getting enough daily values for all substances).

Negative behaviors during pregnancy to avoid proper prenatal care

  • Smoking.

  • Drinking.

  • Use of drugs (ecstasy).

Gene Therapy

  • Techniques can cure genetic diseases through the replacement of faulty genes.

  • Gene Therapy Definition: Insert new genes to replace a faulty disease-causing gene.

  • Considerations for successful gene delivery:

    1. Targeting the right cells.

    2. Activating the gene.

    3. Integrating the gene into the cells.

  • Importance to target the right cells: To find the right cell and deliver genetic material effectively.

  • Importance to activate the gene: To turn on the right gene, minimizing mutation risks.

  • Importance to integrate the gene into the cells: To ensure the gene therapy is effective by becoming part of the overall DNA.

Two types of vectors

  • Viruses

  • Plasmids

Methods for parents to choose the gender of their children

  1. Sperm sorting with artificial insemination.

  2. Preimplantation genetic diagnosis with In Vitro Fertilization.

Sperm sorting with artificial insemination

  • X or Y chromosome is separated from sperm, then the desired sperm is combined with female eggs via artificial insemination.

Preimplantation genetic diagnosis with In Vitro Fertilization

  • Helps potential parents prevent the birth of a child with a serious genetic condition by analyzing egg and sperm combination for abnormalities before developing embryos.

Steps in reproductive cloning

  1. Begin with 1 egg cell and a somatic donor.

  2. Donor cell's nucleus is inserted into the egg cell, changing its genetic info.

  3. Egg cell develops into an embryo and begins cell division.

  4. Once embryo divides to 16 cells, it's transferred to a surrogate mother of the same or related species.

  5. The embryo develops into a genetically identical organism to the somatic cell donor.

Difference between reproductive and therapeutic cloning

  • Therapeutic cloning follows the same process but aims to extract stem cells instead of allowing the embryo to fully develop.

CRISPR

  • Targets the gene of interest via guide RNA.

  • Cas9 role: Binds to the DNA and cuts it, shutting the targeted gene off.

  • Diseases candidates for CRISPR-Cas9 treatment: Infectious diseases and non-viral infections.

  • CRISPR-Cas9 can be tailored to target different genes by attaching RNA to DNA sequences.

Vector Types for Gene Delivery

  • Plasmid: Small, circular DNA molecule used to study/manipulate genes.

    • Target(s): None

    • Activation: None

    • Integration: Do not integrate into host chromosomes.

    • Side Effects: Not as effective.

  • Liposome: Non-viral gene delivery system.

    • Target(s): Not specific

    • Activation: Does not cause activation.

    • Integration: Does not integrate.

    • Side Effects: Not as efficient.

  • Herpes Virus: Large structure capabilities.

    • Target(s): Nervous system cells.

    • Activation: Will cause activation.

    • Integration: Does not integrate but remains active.

    • Side Effects: Not as efficient.

  • Adeno-Associated Virus: Replication-defective, single-stranded DNA virus.

    • Target(s): Not specific.

    • Activation: When gene is expressed.

    • Integration: Can integrate in genome.

    • Side Effects: Uncertain effectiveness.

  • Adenovirus: Modified version of the adenovirus.

    • Target(s): Vascular and smooth muscle cells.

    • Activation: Activates immune response.

    • Integration: Non-integrating.

    • Side Effects: Well tolerated in clinical trials.

  • Retrovirus: Modified retrovirus.

    • Target(s): Mitotic cells.

    • Activation: Integrates into host genome.

    • Effective for gene delivery into rapidly dividing cells.

  • Lentivirus: Derived from HIV.

    • Target(s): Neurons, macrophages, and various body cells.

    • Activation: Infects and transports DNA into other cells.

    • Integration: Integrates into actively transcribed genes (8-10 kb).