Week 1.2.2: Biological Underpinnings Flashcards
The study of the structure and function of genes at a molecular level.
Importance: It helps us understand how genes contribute to various traits and diseases.
Molecular Genetics
One of the 23 pairs of chromosomes in humans
Chromosome 6
A part of chromosome 6 that contains genes related to the immune system and is involved in transplant antigens.
HLA Region (Human Leukocyte Antigen)
Variations in these genes can influence the risk of schizophrenia, suggesting that the immune system may be involved in the development of the disorder
HLA Region
A gene that encodes the dopamine D2 receptor, which is crucial for dopamine signaling in the brain.
Importance: Antipsychotic medications often target this receptor to alleviate symptoms of schizophrenia
DRD2 Gene
Genes involved in the production and regulation of glutamate, a neurotransmitter that influences dopamine release.
Importance: Abnormalities in glutamate signaling are implicated in schizophrenia
Glutamate Genes
A score that sums the effects of multiple genetic variants to estimate an individual’s genetic predisposition to a particular trait or disorder.
Importance: PRS can help predict the likelihood of developing schizophrenia based on genetic factors
Polygenic Risk Score (PRS)
Increase the likelihood of developing the disorder but are not enough on their own to cause it.
These genes interact with environmental factors to influence the risk.
Individual Risk Genes
Involving many genes, each contributing a small effect to the overall risk of developing a condition.
Explanation: Schizophrenia is polygenic, meaning it involves many small genetic factors combined with environmental influences.
Polygenic
Structural changes in the genome where sections of DNA are duplicated or deleted.
Importance: CNVs can significantly impact gene function and are associated with various neurodevelopmental disorders, including schizophrenia
Copy Number Variants (CNV)
A type of CNV where a segment of DNA is missing.
Example: Losing a chunk of DNA that contains several genes.
Deletion
A type of CNV where a segment of DNA is copied more than once.
Example: Having an extra copy of a segment of DNA.
Duplication
The extent to which a genetic variation expresses itself in an individual’s phenotype (observable traits).
Helps us understand how likely it is that a genetic variant will lead to a particular condition.
High means the variant is very likely to cause the condition, while low means it is less likely.
Penetrance
Complications during pregnancy, labor, or delivery that can affect brain development.
Example: Pre-term birth or prolonged labor can impair brain development
Obstetric Events
Abnormal levels of dopamine in the brain, leading to disrupted signaling.
Importance: Excess dopamine release is linked to psychotic symptoms in schizophrenia
Dopamine Dysregulation
A type of imaging test that allows doctors to observe metabolic processes in the body.
Importance: Used to study dopamine synthesis in the brains of people with schizophrenia
PET Scan (Positron Emission Tomography)
A part of the brain involved in motor control and reward.
Importance: In schizophrenia, the striatum produces too much dopamine
Striatum
The junction between two nerve cells where neurotransmitters are released.
Explanation: Dopamine is released into the synapse and binds to receptors on the receiving cell
Synapse
Proteins on the surface of nerve cells that bind to dopamine and transmit signals.
Importance: In schizophrenia, excessive dopamine binds to these receptors, leading to symptoms
Dopamine Receptors
Medications that prevent dopamine from binding to its receptors.
Example: Drugs like haloperidol and chlorpromazine are used to treat schizophrenia by blocking dopamine receptors
Dopamine Blockers
The early symptoms and signs that precede the onset of a disease.
Example: In schizophrenia, the prodrome includes subtle changes in behavior and cognition before full-blown psychosis
Prodrome
A radioactive form of the amino acid dopa used in PET scans to measure dopamine synthesis.
Function: FDOPA is taken up by the brain and converted into dopamine, allowing researchers to visualize dopamine production
Radio-labelled Dopa
A condition where individuals show early signs of potential psychosis but have not yet developed full-blown symptoms.
ARMS (At Risk Mental State)
