Genetics, Epigenetics, and Disease Terminology

Flashcards covering key terminology in genetics, epigenetics, and disease concepts to aid in exam preparation.

Autosomal Dominant Disorders

Diseases usually also present in a parent; both sexes exhibit the trait in equal proportions; no skipping of generations.

Autosomal Recessive Disorders

Typically involves early onset, seen in siblings but generally not in their parents, with a 25% chance of inheritance.

Allele

A variant of a gene.

Dominant Allele

Only one copy is needed for the trait to be expressed.

Recessive Allele

Only expressed if both copies are present.

Homozygous

Having two identical alleles for a specific gene.

Heterozygous

Having two different alleles for a specific gene.

Anticipation

A phenomenon where genetic conditions become more severe or expressed at an earlier age in successive generations.

Carrier

A person with one disease-causing allele who is phenotypically normal.

Cells

The basic building blocks of all living organisms.

Codon

A triplet of RNA base pairs that code for a specific amino acid.

DNA

Deoxyribonucleic acid, the hereditary material and a basic unit making up genes.

Epigenetics

The study of how gene activity is regulated without changes to the DNA sequence.

DNA Methylation

Modification that makes a gene transcriptionally inactive or silent.

X-Inactivation

Random transcriptional silencing of genes on one of the two female X chromosomes.

Histone Modification

Mechanism that plays a role in epigenetic regulation of gene expression.

Micro RNAs (miRNAs)

Small non-coding RNAs that regulate gene expression by silencing specific messenger RNAs.

Expressivity

The degree to which a gene is expressed.

Variable Expressivity

Variation in the effect caused by a particular mutation.

Gene

The basic units of inheritance.

Gene Regulation

The process of turning genes on and off.

Gene Variant (Mutation)

An alteration in the normal DNA sequence.

New Mutation

Occurs when neither parent has a particular gene, but the child is affected.

Mutagen

A substance that increases the frequency of mutations.

Genetic Counseling

Health service providing information and support regarding genetic conditions.

Genetic Screenings

Tests to assess the risk of genetic abnormalities in fetuses or newborns.

Noninvasive Prenatal Testing (NIPT)

Determines risk of certain genetic abnormalities in fetuses.

Newborn Screening

Tests performed on newborns to assess risk for genetic conditions.

Direct-to-Consumer Genetic Testing

Access to personal genetic information without healthcare provider involvement.

Genetic Disorder

Condition caused by mutations in one or more genes.

Genomic Imprinting

The process of gene silencing for specific genes depending on parental origin.

Genotype

The genetic makeup of an individual.

Phenotype

The observable traits or characteristics of an individual.

Incidence Rate

The number of new disease cases in a specific time period divided by the population.

Prevalence Rate

The proportion of the population affected by a disease at a specific time.

Locus

The location of a gene on a chromosome.

Multifactorial Diseases

Disorders caused by both genetic and environmental factors.

Empirical Risks

Risks based on direct observation of data from multifactorial diseases.

Penetrance

The frequency with which a genotype results in the phenotype.

Reduced Penetrance

Occasion where a gene is not always expressed phenotypically.

Pharmacogenetics

Study of genetic causes of variations in drug response.

Pharmacogenomics

Impact of multiple mutations on a patient's drug therapy response.

Precision Medicine

An approach to disease treatment and prevention considering individual variability.

Transcription

The process transferring genetic information from DNA to RNA.

Translation

The assembly of proteins from messenger RNA and transfer RNA interactions.

Sex-Linked Disorders

Disorders associated with genes on the sex chromosomes, primarily expressed in males.

Affected Women in X-Linked Disorders

Express the disease and can transmit it to their children.

Affected Men in X-Linked Disorders

Transmit the disorder 100% to their daughters and none to their sons.

Trisomy 21

Down syndrome, a genetic condition from an extra copy of chromosome 21.

Phenylketonuria (PKU)

A genetic disorder leading to severe intellectual disability if untreated.

Congenital Hypothyroidism

Condition present at birth affecting thyroid function.

Sickle Cell Disease

Genetic disorder characterized by abnormally shaped red blood cells.

Congenital Adrenal Hyperplasia

A genetic condition affecting adrenal gland function.

PKU

Phenylketonuria; a metabolic disorder requiring dietary management.

Genetic Variation

Differences in genes among individuals, often leading to varying traits.

Environmental Factors

External influences that can affect gene expression and disease outcomes.

Heritability

The proportion of variation in a trait among individuals that is due to genetics.

Mutation Rate

Frequency of new mutations in a given gene or organism.

Genetic Engineering

Direct manipulation of an organism's genes using biotechnology.

Gene Therapy

A technique that modifies genes to treat or prevent disease.

Epidemiology

The study of how diseases affect the health and illness of populations.

Clinical Genetics

Field that involves diagnosing and managing genetic disorders.

Genetic Testing

Analyzing DNA to identify changes that may lead to genetic disorders.

Mendelian Inheritance

Patterns of inheritance governed by Gregor Mendel's laws.