Last Review & Stuff Flashcards
__________ is a single phenotype caused by mutations in genes at the same chromosomal locus.
Allelic Heterogeneticy
__________ is a single phenotype caused by mutations in genes at different chromosomal loci.
Locus heterogeneity
___________ is multiple phenotypes resulting from mutations in the same gene.
Clinical Heterogenetiy
T/F-Balanced translocation carriers are not at risk to have unbalanced offspring.
False
Contiguous gene syndrome:______.
Prader Willi Syndrome
______ can result in mutation of a single gene. (PWS or AS)
AS
PWS and AS are the best examples in humans of _______.
Imprinting
Whole Genome sequencing mainly identifies mutations in ______.
Coding Exons
________ is a single phenotype caused by any one of a multiple number of alleles or non-allele (locus) mutations.
Genetic Heterogenatiy
Remember if a disorder is associated with thousands of repeats, it does not occur in the ________.
coding region
If a woman is a carrier of a balanced Robertsonian translocation between chromosomes 14 & 21, how many chromosomes will she have?
45
A woman and her brother are carriers of a balanced Robertsonian translocation between chromosomes 14 and 21. Who has the highest risk to have a child with Down Syndrome?
The risk is always higher in the FEMALE
A woman has a balanced Robertsonian translocation between chromosomes 14 and 21. Her child has DS, how many chromosomes does the child have? How many #21’s?
46, 3 #21’s
What is unique about turner syndrome?
only viable monosomy in humans!
How many barr bodies do you see in a turner syndrome pt?
0
What disorder does non disjunction always occur in male meiosis II?
47, XXY-Kleinfelters
What is the underlying molecular mechanism for type I OI with DI?
Dominant Negative
You need to figure out where to send a patient sample for genetic testing. What resource can you use to find an appropriate lab?
Genetic Testing Registry
A couple has a son with a normally female disorder. Their subsequent risk is _____ than if a daughter had been affected, and the subsequent risk is _____ for a daughter than a son.
Higher…higher
_______: Multiple genes contribute to phenotype, usually each with a small contribution; important in complex traits like diabetes.
Polygenic
______: Genes AND environment contribute to phenotype
multifactoral
What 3 factors increase recurrence risk for a multifactoral trait like clefting?
- # of affected individuals (more=higher risk) 2.Severity (more severe=higher risk) 3.Sex (female is higher risk to pass it to a son)
How is genetic testing different from other types of medical tests?
Implications for other FAMILY members!
A 20 year old woman has PWS due to a parental deletion. If she gets pregnant, what is her risk to have a child with a significant genetic disorder?
50%
