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15 Cards in this Set
- Front
- Back
Name the 3 modes of single gene (mendelian) inheritance?
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Autosomal Dominant
Autosomal Recessive Sex - Linked (X and Y) |
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What are the 5 complications of AD inheritance?
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Variable Expressivity
Non-penetrance or incomplete (age related penetrance) Anticipation Imprinting Mosaicism |
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What is Variable Expressivity and what causes it?
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Phenotype may be different (severity, location) in parent than in child.
Modifiying genes |
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What is non-penetrance?
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When the genetic trait is present, but isn't manifested in the phenotype due to non-genetic causes.
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What is an example of 2 AD disease states?
Which one is an example of age related penetrance? |
Osteogenesis imperfecta
Huntington's disease *** |
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What is mosaicism?
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When the mutated allele only presents in certain tissues.
ex. germline mosaicism only present in sperm. |
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Who is responsible for transmitting the disease in X-linked recessive diseases?
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Carrier (asymptomatic) mothers
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Name two examples of this type of disease state.
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Duchennes muscular dystrophy
Hemophilia A |
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Who is predominantly effected?
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Males
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X-linked dominant traits are very rare and effect who?
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either sex equally.
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When looking at a pedigree, what is the difference between Autosomal dominant and X-linked dominant?
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X-linked dominant
All daughters of affected males are affected. |
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What is Candidate gene analysis?
When is it used? |
Screening/sequencing of candidate genes.
Example = see broken bones. know collagen is most abundant protein in bone. sequence collagen for that mutation. |
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What is Genetic Linkage Analysis?
When is it used? |
It is the use of polymorphic markers (simple sequence variations) that have precise chromosomal locations. Used when there is no obvious candidate gene to find location of diseased gene.
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How is Linkage analysis computed and analyzed?
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It is scored by generating a large amount of data into an equation which gets you a lod score. A lod score over 3 means that you have a greater than 1000:1 chance that the marker is linked to the diseased gene. 1-3 = suggestive. Less than 3 indicate absence of linkage.
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Recessive diseases generate this
Dominant disease can generate both of these |
2 mutated alleles --> loss of gene product
1 mutated allele --> half of normal product (haplosufficiency) or abnormal product reacts with normal product to yield less than 50% normal protein (dominant negative) |