BMB 3 - Psychiatric Evaluation; Genetics of Psychiatry Flashcards
What are the broad questions to be answered in a psychiatric evaluation?
Is a mental illness present?
Does this need referral to psychiatry?
What are the aims of a psychiatric evaluation?
Making a differential.
Dealing with immediate needs; making a treatment plan; fostering an alliance; identifying long-term issues.
What sorts of aspects of the physical exam are important in a psychiatric evaluation?
Cleanliness,
signs of self-injury,
involuntary movements,
demeanor
What is the basis of a mental status clinical interview?
Observational evidence
+
answers to specific questions (in the patient’s own words)
What are the two main categories assessed in the psychiatric evaluation during discussion of the present illness?
Time course
Severity
What important medical history is attained during a psychiatric evaluation?
Past episodes and/or diagnoses;
past suicide attempts or aggressive behavior;
history of substance abuse
What important component’s of one’s social history are assessed during a psychiatric evaluation?
Childhood,
religiosity,
support system,
educational/occupational history,
parental divorce,
quality of relationships
How do mental status exams work?
It is an observational exam – you observe while the patient performs the exam
What sorts of factors are you observing while performing a mental status exam on a patient?
Appearance and behavior
Speech
Motor activity
Mood and affect
Thought content
Thought processes
Perceptual disturbance (hallucinations? Illusions?)
Insight (awareness of current issue)
Judgment (hypothetical decision making)
Cognition (orientation, awareness, memory, abstraction, etc.)
Describe the genetics of most psychological conditions.
A complex mix of polygenic and environmental factors
Do most psychological conditions follow a Mendelian form of inheritance?
No
Which genetic factor explains the increase in incidence of psychological disorders as one ages.
Sporadic mutations
Define heritability in terms of variation.
A statistical concept that describes how much of the variation in a given trait can be attributed to genetic variation (vs environmental)
True/False.
An estimate of the heritability of a trait is specific to one individual.
False.
An estimate of the heritability of a trait is specific to one population.
True/False.
The heritability of a condition can change when environmental circumstances change.
True.
Define genetic inheritance.
The ability for a gene to be passed down through generations
Define both variable expressivity and also incomplete penetrance in terms of individuals with some genotype linked to a genetic disorder.
Variable expressivity - individuals with the relevant genotype show differing levels of severity in their condition.
Incomplete penetrance - some individuals with the relevant genotype show no S/Sy of the disease at all.
True/False.
Genetic heterogeneity refers to the production of single or similar genotypes through different environmental mechanisms.
False.
Genetic heterogeneity refers to the production of single or similar phenotypes through different genetic mechanisms.
What term refers to the condition where multiple, different genes can each lead to a single, common phenotype?
Locus heterogeneity
What term refers to the condition where multiple, different mutations of a single gene can each lead to a single, common phenotype?
Allelic heterogeneity
Alzheimer’s disease is an example of a condition which shows __________ heterogeneity.
Alzheimer’s disease is an example of a condition which shows allelic heterogeneity (i.e. through APP or PSEN1 or PSEN2).
What is assortive mating?
A form of sexual selection in which individuals with similar phenotypes mate with one another more frequently than would be expected under a random mating pattern.
Some diseases, such as Alzheimer’s disease, that are complex diagnoses are due to individual genes.
These genes are known as genes of ________ ________.
Some diseases, such as Alzheimer’s disease, that are complex diagnoses are due to individual genes.
These genes are known as genes of large effect.
Genes of large effect typically cause diseases which follow what sort of age-of-onset and inheritance pattern?
Early age
Mendelian inheritance
For genes of large effect, the risk to first-degree relatives is ____%.
For genes of large effect, the risk to first-degree relatives is 4 %.
An individual is diagnosed with Alzheimer’s disease.
What is the risk of his first-degree relatives being diagnosed in their lives?
4%
(For genes of large effect, the risk to first-degree relatives is 4%.)
True/False.
50 - 75% of patients with risky genotypes for Alzheimer’s disease genes of large effect (e.g. heterozygous for ApoE4) don’t get AD.
True.
Genes of ________ effect are useful in determining pathophysiology and treatment options; although, they do not typically predict likelihood of developing the disorder.
Genes of small effect are useful in determining pathophysiology and treatment options; although, they do not typically predict likelihood of developing the disorder.
The DISC1 gene on chromosome 6 is strongly associated with ____________.
The DISC1 gene on chromosome 6 is strongly associated with schizophrenia (also overlaps with bipolar).
True/False.
There is small association (1%) between the Ch22q11 deletions seen in DiGeorge / velocardiofacial syndromes and schizophrenia.
True.
What is a polygenic risk score in terms of genetic disease?
A statistical analysis based on variation in multiple genetic loci and their association weights
Give some examples of disorders for which polygenic risk scores are used in assessing one’s risk of developing the disorders.
Diabetes mellitus;
some forms of cancer
Describe copy number variant testing.
Cgh microarrays are used to assess numbers of genetic variants of de novo duplications or deletions
Give some examples of diseases for which copy number variant testing is useful in diagnosis.
Autism,
schizophrenia,
epilepsy
What is a gene x environment study?
A study of the influence of life stress on chance of depression in those with long versus short alleles
True/False.
Genetic testing is available and indicated for some diseases (e.g. schizophrenia).
True.
What is the significance of the fact that genetic diseases are almost always partially dependent on some combination of both genetic and environmental factors?
One can often treat the disorders via a reduction in the environmental risk factors
