Genetic Testing and Screening

These flashcards cover the key concepts from the lecture notes on genetic testing and screening.

What is genetic testing?

Genetic testing uses molecular methods to determine if someone has a genetic disorder, will develop one, or is a carrier of a genetic illness.

What are the four types of genetic disorders?

Single-gene, multifactorial, chromosomal, and mitochondrial disorders.

What is the purpose of a genetic counselor?

A genetic counselor helps individuals and families understand and adjust to a genetic diagnosis or the possibility of having a hereditary disorder.

What does PCR stand for?

PCR stands for polymerase chain reaction.

What is the significance of a karyotype?

A karyotype is a picture of chromosomes paired based on size, banding pattern, and centromere position, used to identify chromosomal disorders.

What is a single-gene disorder?

A disorder caused by a change or mutation in one gene, such as sickle cell anemia.

What defines a multifactorial disorder?

A multifactorial disorder is caused by multiple bad genes and environmental factors.

What is the primary purpose of preimplantation genetic diagnosis (PGD)?

PGD allows for testing embryos for genetic conditions before implantation during in vitro fertilization.

What is the primary function of restriction enzymes in genetic testing?

Restriction enzymes cut DNA at specific sequences, allowing identification of the single nucleotide polymorphisms (SNPs).

What are the possible risks associated with amniocentesis?

Amniocentesis carries some risk of miscarriage.

What does cryopreservation refer to?

Cryopreservation is the freezing of eggs, sperm, or embryos for future use.

What technology allows researchers to easily alter DNA sequences?

CRISPR technology.

What ethical concerns are associated with gene therapy?

Gene therapy raises ethical issues regarding potential abuses such as genetic enhancement and designer babies.

What is meant by 'designer babies'?

Designer babies refer to children whose genetic characteristics are selected or altered for desired traits before birth.

What is the function of Taq polymerase in the PCR process?

Taq polymerase is an enzyme that synthesizes new DNA strands during the extension phase of PCR.

What is the genetic basis of Down's syndrome?

Down's syndrome, or Trisomy 21, is caused by an extra copy of chromosome 21.

What is the role of genetic screening?

Genetic screening helps individuals and families determine if they carry genetic diseases or if their children are likely to have them.

What is carrier screening?

Carrier screening tests if individuals carry genes for certain inherited diseases that may be passed on to their children.

What is genetic testing?

Genetic testing uses molecular methods to determine if someone has a genetic disorder, will develop one, or is a carrier of a genetic illness.

What are the four types of genetic disorders?

Single-gene, multifactorial, chromosomal, and mitochondrial disorders.

What is the purpose of a genetic counselor?

A genetic counselor helps individuals and families understand and adjust to a genetic diagnosis or the possibility of having a hereditary disorder.

What does PCR stand for?

PCR stands for polymerase chain reaction.

What is the significance of a karyotype?

A karyotype is a picture of chromosomes paired based on size, banding pattern, and centromere position, used to identify chromosomal disorders.

What is a single-gene disorder?

A disorder caused by a change or mutation in one gene, such as sickle cell anemia.

What defines a multifactorial disorder?

A multifactorial disorder is caused by multiple bad genes and environmental factors.

What is the primary purpose of preimplantation genetic diagnosis (PGD)?

PGD allows for testing embryos for genetic conditions before implantation during in vitro fertilization.

What is the primary function of restriction enzymes in genetic testing?

Restriction enzymes cut DNA at specific sequences, allowing identification of the single nucleotide polymorphisms (SNPs).

What are the possible risks associated with amniocentesis?

Amniocentesis carries some risk of miscarriage.

What does cryopreservation refer to?

Cryopreservation is the freezing of eggs, sperm, or embryos for future use.

What technology allows researchers to easily alter DNA sequences?

CRISPR technology.

What ethical concerns are associated with gene therapy?

Gene therapy raises ethical issues regarding potential abuses such as genetic enhancement and designer babies.

What is meant by 'designer babies'?

Designer babies refer to children whose genetic characteristics are selected or altered for desired traits before birth.

What is the function of Taq polymerase in the PCR process?

Taq polymerase is an enzyme that synthesizes new DNA strands during the extension phase of PCR.

What is the genetic basis of Down's syndrome?

Down's syndrome, or Trisomy 21, is caused by an extra copy of chromosome 21.

What is the role of genetic screening?

Genetic screening helps individuals and families determine if they carry genetic diseases or if their children are likely to have them.

What is carrier screening?

Carrier screening tests if individuals carry genes for certain inherited diseases that may be passed on to their children.

What is prenatal genetic testing?

Testing performed during pregnancy to assess risk for genetic disorders in the fetus.

What is diagnostic genetic testing?

Testing used to confirm or rule out a suspected genetic condition in individuals showing symptoms.

What is predictive genetic testing?

Testing used to identify genetic mutations that increase a person's risk of developing a genetic disorder before symptoms appear.

What is newborn screening?

A public health program that screens infants shortly after birth for certain treatable genetic, endocrine, metabolic, and hematologic conditions.

What is genetic testing?

Genetic testing uses molecular methods to determine if someone has a genetic disorder, will develop one, or is a carrier of a genetic illness.

What are the four types of genetic disorders?

Single-gene, multifactorial, chromosomal, and mitochondrial disorders.

What is the purpose of a genetic counselor?

A genetic counselor helps individuals and families understand and adjust to a genetic diagnosis or the possibility of having a hereditary disorder.

What does PCR stand for?

PCR stands for polymerase chain reaction.

What is the significance of a karyotype?

A karyotype is a picture of chromosomes paired based on size, banding pattern, and centromere position, used to identify chromosomal disorders.

What is a single-gene disorder?

A disorder caused by a change or mutation in one gene, such as sickle cell anemia.

What defines a multifactorial disorder?

A multifactorial disorder is caused by multiple bad genes and environmental factors.

What is the primary purpose of preimplantation genetic diagnosis (PGD)?

PGD allows for testing embryos for genetic conditions before implantation during in vitro fertilization.

What is the primary function of restriction enzymes in genetic testing?

Restriction enzymes cut DNA at specific sequences, allowing identification of the single nucleotide polymorphisms (SNPs).

What are the possible risks associated with amniocentesis?

Amniocentesis carries some risk of miscarriage.

What does cryopreservation refer to?

Cryopreservation is the freezing of eggs, sperm, or embryos for future use.

What technology allows researchers to easily alter DNA sequences?

CRISPR technology.

What ethical concerns are associated with gene therapy?

Gene therapy raises ethical issues regarding potential abuses such as genetic enhancement and designer babies.

What is meant by 'designer babies'?

Designer babies refer to children whose genetic characteristics are selected or altered for desired traits before birth.

What is the function of Taq polymerase in the PCR process?

Taq polymerase is an enzyme that synthesizes new DNA strands during the extension phase of PCR.

What is the genetic basis of Down's syndrome?

Down's syndrome, or Trisomy 21, is caused by an extra copy of chromosome 21.

What is the role of genetic screening?

Genetic screening helps individuals and families determine if they carry genetic diseases or if their children are likely to have them.

What is carrier screening?

Carrier screening tests if individuals carry genes for certain inherited diseases that may be passed on to their children.

What is prenatal genetic testing?

Testing performed during pregnancy to assess risk for genetic disorders in the fetus.

What is diagnostic genetic testing?

Testing used to confirm or rule out a suspected genetic condition in individuals showing symptoms.

What is predictive genetic testing?

Testing used to identify genetic mutations that increase a person's risk of developing a genetic disorder before symptoms appear.

What is newborn screening?

A public health program that screens infants shortly after birth for certain treatable genetic, endocrine, metabolic, and hematologic conditions.

What is a gene?

A unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

What is an allele?

A variant form of a gene.

What is a genotype?

The genetic makeup of an organism, defining the specific alleles inherited.

What is a phenotype?

The observable physical or biochemical characteristics of an organism, as determined by genetic makeup and environmental influences.

What is a mutation?

A change in the DNA sequence.

What is a polymorphism?

A common variation in the DNA sequence among individuals.

What is a 'variant of uncertain significance' (VUS)?

A genetic change whose effect on health is not yet known.

What is a pathogenic variant?

A genetic variant that causes or contributes to a genetic disease.

What is a benign variant?

A genetic variant that does not cause or contribute to a disease.

How are mitochondrial disorders inherited?

They are inherited maternally, from the mother only.

Give an example of a chromosomal disorder besides Down's syndrome.

Klinefelter syndrome or Turner syndrome.

What causes single-gene disorders?

Mutations in a single gene.

What is aneuploidy?

The presence of an abnormal number of chromosomes in a cell, such as having too many or too few.

What is mosaicism in genetics?

The presence of two or more populations of cells with different genotypes in one individual.

What are the three main steps of PCR?

Denaturation, annealing, and extension.

What is the purpose of denaturation in PCR?

To separate double-stranded DNA into single strands by heating.

What happens during the annealing step of PCR?

Primers bind to the complementary sequences on the single-stranded DNA templates.

What is the role of primers in PCR?

Short DNA sequences that define the start and end points of the DNA segment to be amplified.

What is Sanger sequencing?

A method for determining the nucleotide sequence of DNA, widely used for single gene analysis.

What is Next-Generation Sequencing (NGS)?

A high-throughput DNA sequencing technology that sequences millions of DNA fragments simultaneously.

What is whole exome sequencing (WES)?

A type of NGS that sequences all the protein-coding regions (exons) of genes in a genome.

What is whole genome sequencing (WGS)?

A type of NGS that sequences the entire DNA genome of an organism.

What is a microarray in genetic testing?

A high-throughput technology used to profile DNA or RNA, identifying gene expression levels or genetic variations.

How does FISH (Fluorescence In Situ Hybridization) work?

It uses fluorescently labeled probes that bind to specific DNA sequences on chromosomes, allowing visualization.

What is comparative genomic hybridization (CGH)?

A molecular cytogenetic method for analyzing copy number variations (CNVs) in DNA samples.

What are SNPs?

Single nucleotide polymorphisms, which are single base-pair differences in DNA sequences among individuals.

How do restriction fragment length polymorphisms (RFLPs) assist in genetic testing?

They are variations in DNA fragment lengths produced by restriction enzyme digestion, used as genetic markers.

What is MLPA (Multiplex Ligation-dependent Probe Amplification)?

A molecular technique used to detect copy number variations of up to 50 genomic sequences simultaneously.

What is population screening?

Genetic screening offered to all individuals in a defined population, regardless of family history.

What is targeted screening?

Genetic screening offered to individuals or families considered to be at higher risk for a specific genetic condition.

How does non-invasive prenatal testing (NIPT) work?

It analyzes cell-free DNA fragments from the placenta circulating in the mother's blood to screen for chromosomal abnormalities.

What is chorionic villus sampling (CVS)?

A prenatal diagnostic test that involves taking a sample of placental tissue for genetic analysis.

What conditions are commonly screened for in newborn screening?

Phenylketonuria (PKU), congenital hypothyroidism, and sickle cell disease are common examples.

What is preimplantation genetic screening (PGS)?

Genetic screening of embryos for chromosomal abnormalities before implantation, often for fertility purposes.

What is the difference between PGD and PGS?

PGD (Preimplantation Genetic Diagnosis) screens for specific known genetic disorders, while PGS (Preimplantation Genetic Screening) screens for general chromosomal abnormalities.

What is pharmacogenetics/pharmacogenomics?

The study of how genes affect a person's response to drugs, used to personalize drug treatment.

What is direct-to-consumer (DTC) genetic testing?

Genetic tests that are marketed directly to consumers without requiring a physician's order.

What is informed consent in genetic testing?

The process by which a patient agrees to a medical procedure, such as genetic testing, after understanding its risks, benefits, and alternatives.