Molecular Diagnostic Lectures Cue Cards

A comprehensive set of flashcards focused on key vocabulary and concepts related to genetic testing and molecular biology.

Genetic Testing

A type of medical test that identifies changes in genes, chromosomes, or proteins.

Chromosomes

Structures within cells that contain DNA.

Proteins

Molecules that perform various functions within the body.

Newborn Screening

Early identification of genetic disorders in newborns.

Prenatal Testing

Identifying genetic abnormalities in a fetus before birth.

Predictive DNA Testing

Assessment of the risk of developing genetic disorders.

DNA Fingerprinting

Techniques for identifying individuals based on their unique DNA patterns.

Pharmacogenetic Testing

Evaluating how genes affect individual responses to medications.

Analytical Validity

Effectiveness in predicting the presence or absence of specific genes or genetic changes.

Clinical Utility

The test's ability to provide useful information for diagnosis, treatment, management, or prevention of a disease.

Autosomal Dominant

An inheritance pattern where only one copy of the mutated gene is needed for the disease to manifest.

CAG repeats

A type of mutation where specific DNA segments repeat, associated with Huntington's Disease.

Epigenetics

The study of inheritable changes in gene expression in response to environmental factors.

DNA Methylation

A process where methyl groups are added to DNA, affecting gene expression.

Histone Modification

Chemical changes to histone proteins that influence gene accessibility and gene expression.

Genomic Imprinting

Involves expression of genes based on the parent of origin due to DNA methylation patterns.

Variable Number Tandem Repeats (VNTR)

Sections of DNA where a short nucleotide sequence is repeated multiple times, showing variations among individuals.

Short Tandem Repeats (STR)

A type of VNTR where short sequences of DNA bases are repeated, used for individual identification.

Therapeutic Index (TI)

The ratio of a drug's toxic dose to its effective dose, indicating safety margins.

Genome Sequencing

Comprehensive analysis of an organism's entire DNA sequence, including both coding and non-coding regions, to identify mutations or variants.

Microarray Technology

A method for analyzing gene expressions across various conditions.

Primary goals of Genetic Testing

Diagnosis of genetic conditions, assessment of disease risk, and guidance for medical treatment.

Main function of Chromosomes

To safely package, protect, and regulate the expression of DNA within cells.

Diversity of Protein functions

Enzymatic catalysis, structural support, transport, signaling, and immune defense.

Clinical impact of Newborn Screening

Enables early intervention, often preventing severe symptoms or irreversible damage from genetic conditions.

Common methods for Prenatal Testing

Non-Invasive Prenatal Testing (NIPT), amniocentesis, and chorionic villus sampling (CVS).

Utility of Predictive DNA Testing

Allows individuals to make informed decisions about lifestyle, preventative care, and family planning based on future disease risk.

Key applications of DNA Fingerprinting

Forensic science for criminal investigations, paternity testing, and identification of disaster victims.

Benefits of Pharmacogenetic Testing

Personalizes medicine by predicting drug efficacy, optimizing dosage, and minimizing adverse drug reactions.

Factors determining Clinical Utility

Whether test results inform medical decisions, improve patient outcomes, or lead to effective interventions for a condition.

Inheritance probability for Autosomal Dominant

If one parent is affected and heterozygous, each child has a 50% chance of inheriting the condition.

Mechanism for CAG repeat diseases

Expanded CAG repeats lead to an abnormal protein product that causes cellular dysfunction and neurodegeneration.

Key feature of Epigenetic changes

They modify gene activity without altering the underlying DNA sequence and can be influenced by environment, diet, and lifestyle.

Role of DNA Methylation in gene silencing

Often occurs at CpG islands in promoter regions, leading to transcriptional repression by blocking transcription factors or recruiting repressor proteins.

Impact of Histone Modification on chromatin structure

Acetylation generally loosens chromatin for gene activation, while deacetylation or methylation can condense it for repression.

Example diseases linked to Genomic Imprinting

Prader-Willi syndrome and Angelman syndrome, caused by abnormalities in imprinted regions on chromosome 15.

Characteristics of VNTRs

They are typically longer than STRs and show high variability in repeat numbers, making them valuable for genetic identification.

Advantages of STRs in forensics

Their shorter length allows for easier amplification from degraded DNA samples using PCR, making them ideal for forensic DNA profiling.

Implications of a low Therapeutic Index (TI)

Drugs with a low TI have a narrow margin between effective and toxic doses, requiring careful monitoring to prevent adverse effects.

Exome Sequencing

Focuses specifically on analyzing the protein-coding regions (exons) of the genome to identify disease-causing mutations.

How Microarray Technology works

Relies on the hybridization of fluorescently labeled sample DNA/RNA to specific probes immobilized on a solid surface to measure gene expression levels.