Mutations & Genetic Analysis Flashcards
<p>What are the different kinds of chromosomal abnormalities?</p>
<p>Numerical</p>
<p>Structural</p>
<p>Mutational</p>
<p>When does first trimester begin and end?</p>
<p>First day of someone's last period and lasts until the end of week 12 of an embryo's life</p>
<p>What percentage of miscarriages during the first trimester are due to chromosomal abnormalities?</p>
<p>50%</p>
<p>What are the kinds of numerical abnormalities?</p>
<p>Trisomy (additional chromosomes)</p>
<p>Monosomy (less chromosomes)</p>
<p>What is trisomy?</p>
<p>Additional chromosomes</p>
<p>What is monosomy?</p>
<p>Less chromosomes</p>
<p>What are examples of trisomy?</p>
<p>Patau syndrome (additional 13)</p>
<p>Edwards syndrome (additional 18)</p>
<p>Downs syndrome (additional 21)</p>
<p>Klinefelter (boys have additional X)</p>
<p>Patau syndrome is an additional what chromosome?</p>
<p>13</p>
<p>Edwards syndrome is an additional what chromosome?</p>
<p>18</p>
<p>Downs syndrome is an additional what chromosome?</p>
<p>21</p>
<p>Klinefelter syndrome is an additional what chromosome?</p>
<p>Boys have an additional X chromosome</p>
<p>What is an example of a monosomy?</p>
<p>Turner's syndrome (female missing all or part of X chromosome)</p>
<p>What chromosome is missing in turner's syndrome?</p>
<p>Female missing all or part of X chromosome</p>
<p>What is disomy?</p>
<p>The condition of having a chromosome represented twice in a chromosomal complaint</p>
<p>What is aneuploudy?</p>
<p>The presence of an abnormal amount of chromosomes in a cell</p>
<p>What is nondisjunction?</p>
<p>Failure of chromosomes to seperate properly during cell division</p>
<p>What may the origin of nondysjunction be?</p>
<p>Paternal or maternal, with different kinds of trisomys having different likeliness of each</p>
<p>Most autosomal are maternal and sex monosomy sex linked is paternal and trisomy sex linked is even</p>
<p>What are examples of autosomal chromosomes aneuploidy syndromes?</p>
<p>Down syndrome (trisomy 21)</p>
<p>Patau syndrome (trisomy 13)</p>
<p>Edwards syndrome (trisomy 18)</p>
<p>What are the chances of inheriting trisomy 21 (down syndrome)?</p>
<p>1/650</p>
<p>What causes the chances of inheriting down syndrome to increase?</p>
<p>Increases with maternal age</p>
<p>What are some characteristics of down syndrome?</p>
<p>Facial dysmorphologies (birth defects that affect anatomy)</p>
<p>IQ less than 50</p>
<p>Alzheimer's disease in later life</p>
<p>What is down syndrome normally due to?</p>
<p>Non-dysjunction of chromosome 21 which is usually maternal (95%)</p>
<p>Translocation (5%)</p>
<p>What is the occurance of trisomy 13 (patau syndrome)?</p>
<p>1/1000</p>
<p>What are some characteristics of patau syndrome?</p>
<p>Multiple dysmorphic features and mental retardnation</p>
<p>Very few survive beyond first year</p>
<p>What is patau syndrome normally caused by?</p>
<p>Nondysjunction of chromosome 13 (90%)</p>
<p>Translocation (10%)</p>
<p>What is the occurance of trisomy 18(edwards syndrome)?</p>
<p>1/3000</p>
<p>What are some characteristics of edwards syndrome?</p>
<p>Severe developmental problems</p>
<p>Most die in first year</p>
<p>What is edwards syndrome normally caused by?</p>
<p>Nondysjunction (90%)</p>
<p>What are some sex chromosomes aneuploidy syndromes?</p>
<p>Turner's syndrome (45, X)</p>
<p>Klinefelter syndrome (47, XXY)</p>
<p>What is the occurance of turner's syndrome?</p>
<p>1/5000</p>
<p>What are some characteristics of Turner's syndrome?</p>
<p>Females of short stature and infertile</p>
<p>Neck webbing and widely spaced nipples</p>
<p>Intelligence and lifespam normal</p>
<p>What is the occurance of Klinefelter syndrome?</p>
<p>1/1000</p>
<p>What are characteristics of Klinefelter syndrome?</p>
<p>Tall stature, long limbs</p>
<p>Males infertile, small testis</p>
<p>Mild learning difficulties</p>
<p>What can structural abnormalities be?</p>
<p>Balanced or unbalanced</p>
<p>What are examples of chromosomal structural abnormalities?</p>
<p>Translocation</p>
<p>Deletions</p>
<p>Insertions</p>
<p>Inversions</p>
<p>What are the two kinds of chromosomal translocation?</p>
<p>Reciprocal (involving breaks in two chromosomes with formation of two new deriviative chromosomes)</p>
<p>Robertsonian (fusion of two acrocentric chromosomes)</p>
<p>What is reciprocal translocation?</p>
<p>Breaks in two chromosomes with formation of two new derivative chromosomes</p>
<p>What is robertsonian translocation?</p>
<p>Fusion of two acrocentric chromosomes</p>
<p>What are acrocentric chromosomes?</p>
<p>Chromosomes in which the centromere is located quite near one end of the chromosome</p>
<p>What is balanced translocation?</p>
<p>Translocation where no genetic material is lost (reciprical translocation)</p>
<p>What is unbalanced translocation?</p>
<p>When someone inherits too much of one chromosome and not enough of another</p>
<p>What does robertsonian translocation result in the loss of?</p>
<p>The short arms of the two acrocentric chromosomes</p>
<p>Where may genetic mutations occur?</p>
<p>Germline or somatic</p>
<p>What does genetic mutation lead do?</p>
<p>Gene disruption</p>
<p>Disease associated</p>
<p>What do genetic mutations not have?</p>
<p>Phenotypic effect</p>
<p>What are different types of genetic mutations?</p>
<p>Non-coding</p>
<p>Coding</p>
<p>What are the different kinds of coding genetic mutations?</p>
<p>Point (only that codon is affected)</p>
<p>Frameshift (codons from that point are affected)</p>
<p>What do point mutations affect?</p>
<p>Only that codon</p>
<p>What do frameshift mutations affect?</p>
<p>Codons from that point</p>
<p>What are examples of point mutations?</p>
<p>Silent (mutation with no change to coded amino acid)</p>
<p>Missense (single nucleotide change results in different amino acid)</p>
<p>Nonsense (single nucleotide change results in stop codon)</p>
<p>What is a silent mutation?</p>
<p>Mutation with no change to coded amino acid</p>
<p>What is a missense mutation?</p>
<p>Single nucleotide change results in different amino acid</p>
<p>What is a nonsense mutation?</p>
<p>Single nucleotide change results in stop codon</p>
<p>What are examples of frameshift mutations?</p>
<p>Deletion (part of sequence lost)</p>
<p>Insertion (insertion of additional nucleotide)</p>
<p>What is a deletion mutation?</p>
<p>Part of sequence is lost</p>
<p>What is an insertion mutation?</p>
<p>Insertion of additional nucleotides</p>
<p>What are the two types of point mutations in relation to purines and pyrimidines?</p>
<p>Transitions (swapping purine for purine (A and G) or pyrimidine for pyrimidine (C and T))</p>
<p>Transversions (swapping purines to pyrimidines and vice versa)</p>
<p>What are transition mutations?</p>
<p>Swapping a purine for a purine or a pyrimidine for a pyrimidine</p>
<p>What are transversion mutations?</p>
<p>Swapping a purine for a pyrimidine and vice versa</p>
<p>What are the purines?</p>
<p>Adesine and guanine</p>
<p>What are the pyrimidines?</p>
<p>Cytosine and thymine</p>
<p>What does the nomenclature of a mutation describe?</p>
<p>Its location in the genome</p>
<p>How is a mutation named?</p>
<p>Describes number from the translation start site (c.10 is 10 nucleotides further into an exon, and c.10+2 is 2 nucleotides into the intron after the exon)</p>
<p></p>
<p>What is an example of naming a point mutation?</p>
<p>c.586C>T (a substitution of a C nucleotide for a T nucleotide at nucleotide 586 within gene)</p>
<p>What is an example of naming a deletion?</p>
<p>c485_488del (a deletion of four nucleotides within a gene, from position c.485 up to and including nucleotide 488)</p>
<p>What is an example of naming a duplication mutation?</p>
<p>c.482_484dup (a duplication of three nucleotides within a gene, from position c.482 up to and including nucleotide c.484)</p>
<p>What is an example of naming an insertion mutation?</p>
<p>c300insATC (an insertion of three nucleotides within a gene, A, T and C, occuring directly after position c.300)</p>
<p>Mutations can be detected by using what?</p>
<p>Polymerase chain reaction (PCR)</p>
<p>Gel electrophoresis</p>
<p>Restriction fragment length polymorphisms (RFLP) analysis</p>
<p>Amplifications refractory mutation system (ARMS)</p>
<p>DNA sequencing</p>
<p>What do we need for polymerase chain reaction (PCR)?</p>
<p>Sequencing information</p>
<p>Oligonucleotide primers</p>
<p>DNA</p>
<p>Nucleotides</p>
<p>DNA polymerase</p>
<p>What is the process of polymerase chain reaction (PCR)?</p>
<p>1) Denaturing (heated to seperate strands)</p>
<p>2) Annealing (cooled to enable DNA primers to attach)</p>
<p>3) Extending (heated and new strand of DNA made by DNA polymerase)</p>
<p>4) Repeated 20 to 40 times, doubling the amount of DNA each time</p>
<p>What does gel electrophoresis do and how?</p>
<p>Seperates DNA fragments by size</p>
<p>It does this by applying an electric field, and because DNA is negatively charged it moves through the agrose gel mix</p>
<p>What are the advantages of PCR?</p>
<p>Speed</p>
<p>Ease of use</p>
<p>Sensitive</p>
<p>Robust</p>
<p>What can PCR be used for?</p>
<p>DNA cloning</p>
<p>DNA sequencing</p>
<p>In vitro mutagenesis</p>
<p>Gene identification</p>
<p>Gene expression studies</p>
<p>Forensic medicine</p>
<p>Typing genetic markers</p>
<p>Detection of mutations</p>
<p>How does amplification refractory mutation system (ARMS) work?</p>
<p>1) Uses constitutive primer which may be a normal primer or a mutant primer</p>
<p>2) If the DNA is that which is expected the normal primer will cause amplification and the mutant primer will not because the bases will not pair</p>
<p>What are the advantages of ARMS?</p>
<p>Cheap</p>
<p>Labelling not required</p>
<p></p>
<p>What are the disadvantages of ARMS?</p>
<p>Need sequence information</p>
<p>Limited amplification size</p>
<p>Limited amount of product</p>
<p>Infidelity of DNA replication</p>
<p>Electrophoresis required</p>
<p>Primer design critical</p>
<p>What is restriction endonucleases?</p>
<p>Enzymes from bacterial cells that degrade the DNA of invading viruses</p>
<p>Recognise specific DNA sequences, usually 4 to 8 base pairs and always cut DNA at the same site</p>
<p>What are advantages of restriction endonucleases?</p>
<p>Simple</p>
<p>Cheap</p>
<p>Non-radioactive</p>
<p>What are disadvantages of restriction endonucleases?</p>
<p>Requires gel electrophoresis</p>
<p>Not always feasible</p>
<p>What is DNA sequencing?</p>
<p>A chain termination method that uses dideoxynucleotides</p>
<p>What are advantages of DNA sequencing?</p>
<p>Gold standard for mutation detection</p>
<p>Automation and high throughput</p>
<p>Fast (18 billion base paires in 4 days, 6 human genomes)</p>
<p>What are disadvantages of DNA sequencing?</p>
<p>Poor quality sequence read</p>
<p>Expensive equipment</p>
<p>What should you consider when deciding what detection method you should use?</p>
<p>Direct test</p>
<p>Quick and easy</p>
<p>Cheap</p>
<p>Sensitivity</p>
<p>Specificity</p>
