Week 1 Flashcards
(151 cards)
Penetrance
on/off switch
- If person has mutation they either effected or not effected
- NOT influenced by level of phenotype expression
Expressivity
dimmer function
- Light is on, but trying to determine SEVERITY / range of expressivity
- Patient has mutation, but there is a range of severity levels
Pleitropy
gene that has multiple effects within the body
- How broad/how many different areas are effected
- Polysystemic or Monosystemic
Mendel’s 2 laws are…
- Mendel’s Law of Segregation: Alleles segregate (at meiosis) into the gametes
- Mendel’s Second Law of Independent Assortment: the segregation of each pair of alleles is independent
3 threats to mendelian inheritance
penetrance
pleitropy
expressivity
The human genome is _________ and organized in a ______________
dynamic
non-random manner
There is an average of _______ SNPs every _________ bp between any two randomly chosen human genomes.
We are 99.9% identical but this still means we have _________ differences
1
1000 bp
3 million
The 4 types of variations that can occur between genomes are…
1) Insertion/Deletion Polymorphisms
2) Single Nucleotide Polymorphisms
3) Copy Number Variations
4) Other structural variations (inversion, duplications, translocations, large scale insertions/deletions)
Minisatellites are ____________ polymorphisms and consist of ___________. They are also known as _____________
insertion-deletion polymorphisms
consist of tandemly repeated 10-100 bp blocks of DNA
(aka Variable Number Tandem Repeats VNTR)
Microsatellites are _____________ polymorphisms and consist of __________. They are also known as ___________ and a common example is ____________
insertion-deletion polymorphism
di-, tri-, tetra- nucleotide repeats
AKA Short Tandem Repeat Polymorphisms (STRP)
EX) CAG repeats - abnormal CAG repeats in Huntington’s disease dictate if individual gets disease or not
SNPs can be detected by _________, and are used in _________ because they are so widely distributed
PCR
can be used in genetic fingerprinting
Copy Number Variations can vary in size from _______-______ and are the primary type of ________ variation.
200bp - 2 Mb
structural
CNV can be identified using ________
array comparative genomic hybridization
microarray, but with DNA
1q21 is a region on the genome that is _______ and is associated with _______ different diseases
unstable
12 different diseases
1q21
- contains duff 12-20, highly variable protein coding region
- humans have most copies
- farther you get from humans the less copies
- thought to be involved in human brain evolution
- more instability in 1q21 = increase duff 1220 copy number –> increase in brain size
1q21 deletion –>
1q21 duplication –>
deletion –> schizophrenia, microcephaly
duplication –> autism, macrocephaly
G-C rich regions make up ____% of the genome, and A-T rich regions make up ____%
GT = 38% AT = 54%
GC and AT rich regions are used in finding _________
chromosomal banding patterns
Genome sequencing is focused on _____ regions with > ______ sequence gaps still remaining, and there is no completely sequenced and assembled human genome.
euchromatic, >200
Genome Composition:
1) _____ = translated (protein coding)
2) 20-25% = __________
3) ______% = “single copy” sequences
4) 40-50% = _________
1) 1.5% is translated (protein coding)
2) 20-25% is represented by genes (exons, introns, flanking sequences involved in regulating gene expression)
3) 50% “single copy” sequences
4) 40-50% classes of “repetitive DNA”
NextGen sequencing relies on ______ sequences, therefore _________ regions are typically unexamined such as _______
short read
complex, highly duplicated regions
such as 1q21
Missing Heritability
defined as the fact that single genetic variations cannot account for much of the heritability of diseases, behaviors, and other phenotypes.
Explain the relationship between gene duplication and evolution and problems with this
- CNV involved in rapid, recent evolutionary change
- link between evolutionarily adaptive copy number increases and increase in human disease
- one gene copy carries out critical function, the other is free to vary
CNV regions are often enriched for _________, __________, and __________
human specific gene duplication
genome sequence gaps
recurrent human diseases