HG 11 Reproductive Technology, Genetic Testing, and Gene Therapy

Flashcards on Reproductive Technology, Genetic Testing, and Gene Therapy

First IVF Success

The first IVF baby was born on July 25, 1978, after nine years of modifying techniques and 80 failed attempts.

Normal Reproduction

Healthy gametes, a place for fertilization, and a place for the baby to develop are required for successful reproduction.

Infertility Prevalence

Infertility affects approximately 1 in 6 couples.

Causes of Infertility

Female and male infertility each account for about 40% of infertility cases.

When to Examine Infertility

Infertility usually is examined after one year of trying, or after six months if the woman is older than 35.

Primary Infertility

Couples that have not had a child yet

Secondary Infertility

Couples that already have a child

Causes of Female Infertility

No or damaged ovaries, Polycystic Ovarian Syndrome, Low or no estrogen, Blockages, endometriosis

Endometriosis

Occurs when the endometrium grows in abnormal locations, such as outside the uterus, bowel, bladder, or brain.

Varicocele

Low sperm count, affecting 40% of first-time infertility cases and 80% of second-time cases.

Varicocele Description

Swelling of the veins in the testes, leading to poor valve function and blood pooling.

Other Causes of Infertility

Overweight/underweight leading to hormonal changes, High temperature, radiation, Herbicides, plastics, heavy metals, tobacco, Bacteria, viruses, chronic disease, Stress, exercise, diet, Smoking, Poverty, infections, education

Assisted Reproductive Technologies

Artificial Insemination, Egg retrieval or donation, In vitro Fertilization, GIFT and ZIFT, Surrogacy, Newer technologies

Artificial Insemination (IUI)

Fresh donor sperm is injected into a woman’s uterus during her menstrual cycle, with the hope that normal fertilization and pregnancy will follow.

Egg Retrieval or Donation

Hormones are used to stimulate egg production, or a donor is used. Eggs are sorted to remove those that are too old or too young, fertilized outside the body, and the resulting embryo are implanted.

In Vitro Fertilization (IVF)

Gametes are combined in a sterile dish and allowed to develop until the blastocyst stage, then implanting the embryo.

Intracytoplasmic Sperm Injection (ICSI)

Involves injecting sperm directly into the egg cell and is used as a treatment for male infertility, low sperm count, or previous unsuccessful IVF attempts.

Physiological ICSI (PICSI)

Uses specialized petri dishes containing hyaluronan drops for the selection of the healthiest sperm and is usually only done if other techniques have failed.

Gamete Intrafallopian Transfer (GIFT)

Sperm and eggs are collected and placed directly into the fallopian tubes. Fertilization and gestation occur normally.

Zygote Intrafallopian Transfer (ZIFT)

Eggs are fertilized externally by IVF and implanted into the fallopian tube immediately after fertilization. The pregnancy is then allowed to progress from there.

Genetic surrogacy

Uses the surrogate’s eggs and artificial insemination.

Gestational surrogacy

The surrogate is only used to carry the child.

Maternal spindle transfer

Material is swapped between the mother's and donor's egg prior to fertilization.

Pronuclear transfer

Material is swapped between the mother's and donor's egg after fertilization.

Risks of Using ART

Ovarian Hyperstimulation Syndrome, Increased risk of multiple births, Increased premature births, Low birth weight, Chromosomal abnormalities, Ectopic pregnancy

Genetic Testing

Voluntary, used to identify disease gene carriers.

Genetic Screening

May be legally required in populations where there is a high risk of disease.

Newborn Screening Tests

Done in all hospitals in Australia 48-72 hours post-birth. A heel prick is used to collect blood, and tests are conducted for conditions like cystic fibrosis, hypothyroidism, and phenylketonuria.

Carrier Testing

Done on families or ethnic groups with a history of disease. It detects carriers and determines the risk of passing on the disorder.

Prenatal Testing

Involves testing the fetus for over 200 diseases. Methods include ultrasound, amniocentesis, and chorionic villus sampling.

Pre-implantation Genetic Diagnosis (PGD)

Involves testing embryos at 6-8 cells post-fertilization. A single cell is removed, and DNA is extracted and amplified using PCR. This is done in cases of family history or positive carrier screening results for autosomal recessive or X-linked disorders.

Polar Body Biopsy

Involves testing eggs before fertilization. The polar body is removed and examined by PCR to determine which X-chromosome is in the egg cell, helping to detect X-linked recessive diseases.

Gene Therapy

Uses recombinant-DNA methods to correct individual mutated genes. A normal gene is inserted, and a functional protein is produced using chemical, physical, or viral methods.

Unwanted Immune Reactions

The immune system may recognize the viruses as foreign and attack them.

Targeting the Wrong Cells

Healthy cells may be damaged, leading to illness, disease, or cancer.

Genetic Counseling

Explains the risks of certain diseases to families.

Somatic Gene Therapy

Targets body cells.

Germ-line Gene Therapy

Targets sperm and egg cells for gene transfer.

Enhancement Gene Therapy

Uses genes to enhance specific traits.

PCOS Treatment

weight loss, medications, or in vitro fertilization

Low Sperm count

Heating the testes too much, Hormonal imbalances, Retrograde ejaculation