Unit 2

Medical Interventions unit 2

Gene

Gene

A discrete unit of hereditary information consisting of a specific nucleotide sequence of DNA.

Genetic Counseling

A process of communication that deals with the occurrence or risk that a genetic disorder will occur in a family, helps with testing, and provides information people need to make informed choices.

Genome

The complement of an organism's genes; an organism's genetic material.

Genetic Testing

The use of methods to determine if someone has a genetic disorder, will develop one, or is a carrier.

Genetic Disorder

A disease caused by abnormalities in an individual's genetic material.

Single Gene Disorder

Mutations that occur in the sequence of one gene, where the protein product can't carry out its normal job. Inherited through autosomal dominant, recessive, or sex-linked patterns. Examples include Sickle cell anemia.

Multifactorial Disorder

A combination of environmental factors and mutations in multiple genes. Examples include heart disease and breast cancer.

Chromosomal Disorder

Abnormalities in the number or structure of chromosomes. Detected through karyotype analysis. Examples include Down syndrome.

Mitochondrial Disorder

Rare mutations in the nonchromosomal DNA of mitochondria, passed solely from mother to child. Examples include Leber's hereditary optic neuropathy.

Carrier Screening

Determines if a person is a carrier of a recessive gene. Examples include Tay-Sachs and sickle cell disease.

Preimplantation Genetic Diagnosis (PGD)

Used in IVF to diagnose genetic disorders before the embryo is implanted into the uterus.

Fetal Screening/Prenatal Diagnosis

Allows parents to diagnose a genetic condition in their developing fetus. Examples include amniocentesis, CVS, and ultrasounds.

Newborn Screening

Detects genetic and medical conditions in newborns so that they can be treated early on.

Polymerase Chain Reaction (PCR)

A technique that involves copying short pieces of DNA and making millions of copies in a short period of time.

Denaturation

Step 1 of PCR, where the template DNA is heated to break the hydrogen bonds and separate the two strands.

Annealing

Step 2 of PCR, where the primers attach to the complementary sequence in the DNA template.

Extension

Step 3 of PCR, where Taq polymerase adds nucleotides to the annealed primer.

Genotype

The genetic makeup of an organism, written in terms of alleles. Example:Tt.

Phenotype

The physical and physiological traits of an organism. Example:blue eyes.

Single Nucleotide Polymorphism (SNP)

One base-pair variation in the genome sequence.

Restriction Enzyme

A degradative enzyme that recognizes specific nucleotide sequences and cuts up DNA.

Chorionic Villus Sampling (CVS)

A technique for diagnosing genetic and congenital defects in a fetus by removing and analyzing a sample of the fetal portion of the placenta.

Amniocentesis

A technique for determining genetic abnormalities in a fetus by analyzing the amniotic fluid obtained through a needle inserted into the uterus.

Ultrasounds

Imaging technique that uses sound waves to create images of the developing fetus.

Duchenne Muscular Dystrophy

Sex-linked recessive disorder that causes muscle weakness due to the body's inability to produce the protein dystrophin.

Cystic Fibrosis

Autosomal recessive disorder that causes mucus to clog the lungs and other lung problems due to problems in the CFTR protein.

Huntington's Disease

Autosomal dominant disorder that causes a severe decline in thinking and reasoning skills and abnormal movements due to a defective protein called Huntington.

Down Syndrome

Caused by a problem with chromosome 21, characterized by physical defects, small stature, and mental retardation.

Leber Hereditary Optic Neuropathy

Mitochondrial disorder characterized by vision loss due to a defective enzyme responsible for converting oxygen, fats, and sugars to energy.

Alzheimer's Disease

Neurodegenerative disease characterized by dementia and memory loss, caused by a buildup of beta-amyloid plaques and neurofibrillary tangles.

Screening Test

Shows the likelihood of a child having a particular disorder or condition, but not a definitive confirmation.

Diagnostic Test

Provides a definite answer as to whether or not a child will be born with a particular disorder or condition.

Maternal Serum Screens

Noninvasive screening that measures hormones in the mother's blood to assess the risk of neural tube defects and chromosomal disorders in the fetus.

hCG (human chorionic gonadotropin)

Hormone produced by the placenta during pregnancy, abnormal levels suggest chromosomal disorders like Trisomy 21.

Nuchal Translucency Ultrasound

Special ultrasound that measures the nasal bone and fluid in the back of the neck to assess the risk of birth defects.

Cell-Free Fetal DNA Analysis

Noninvasive screening that tests the fetus's DNA circulating in the mother's blood to identify genetic disorders and determine the baby's blood type and gender.

Glucose Tolerance Test

Used to see if the mother has developed gestational diabetes by measuring glucose levels before and after consuming a sugary solution.

Gestational Diabetes

Temporary disease occurring in some pregnancies where placental hormones cause high blood sugar.

Plasmid

Circular piece of double-stranded DNA used as a non-viral vector in gene therapy.

Liposome

Plasmids packaged into miniature lipid-based packets used as a viral vector in gene therapy.

Herpes Simplex Virus

Double-stranded DNA virus used as a viral vector in gene therapy, particularly targeting and infecting cells of the nervous system.

Adeno-Associated Virus

Non-pathogenic virus with single-stranded DNA used as a viral vector in gene therapy, capable of infecting dividing and nondividing cells.

Adenovirus

Common cold-causing virus with double-stranded DNA used as a viral vector in gene therapy, infects dividing and nondividing cells effectively.

Retrovirus

RNA virus that carries genetic material, used as a viral vector in gene therapy, only infects dividing cells and can integrate into the host genome.

Gene Therapy

The alteration of the genes of a person afflicted with a genetic disease to treat or cure the disease.

Vector

An agent, such as a plasmid or virus, that contains or carries modified genetic material and can be used to introduce extra genes into the genome of an organism.

Insert Strategy

A gene therapy strategy where a functional gene is given to a patient to provide their body with the means to make a functional protein.

Disable Strategy

A gene therapy strategy where a dysfunctional gene is disabled to eliminate the impact of the protein it produces.

Repair Strategy

A gene therapy strategy where a dysfunctional gene is repaired so that it can produce a functional protein.

In Vitro Fertilization

A procedure in which gametes are fertilized in a dish in the laboratory, and the resulting zygote is implanted in the uterus for development.