Unit 4 Flashcards
The Genetic Information Nondiscrimination Act of 2008 includes which of the following protections?
An individual can not be denied health insurance on the basis of a genetic test
Under the Genetic Information Non-Discrimination Act of 2008…
a person cannot be denied health insurance because they have a genetic variation that is associated with a small increased risk for breast cancer
True or False: Genetic tests are powerful, but still too expensive to use to improve standard medical care of most people in the US
False
Which of the following DNA sequences in the genome could be referred to as “non-coding” DNA? (Regulatory elements, introns, exons, the long sequences of DNA nucleotides in between adjacent genes on a chromosome)
Regulatory elements, introns, and the long sequences of DNA nucleotides in between adjacent genes on a chromosome
What are introns?
The intervening stretches of DNA that are removed during mRNA processing, so they do not code for amino acids in proteins
Where are regulatory elements?
Upstream from the nucleotides in DNA that code for mRNA
True or False: Genetic variations always change the coding sequence of a protein?
False, genetic variations usually occur in non-coding regions of genes since these regions make up over 99% of the genome
True or False: A coding sequence is the part of a gene that determines if that gene is expressed in a certain cell type or tissue of the body?
False, non-coding regions near the beginning of the gene contain regulatory regions that control which tissues in the body express a specific gene
Which explains why some SNPs don’t result in any changes to the protein produced by a cell?
Many mutations occur in non-coding regions outside of the gene, many DNA mutations are corrected by repair enzymes, and some proteins can have no effect on proteins
What is an example of an SNP?
Replacement of a G=C base pair with an A=T base pair
What best describes the relationship between a gene and DNA?
A gene is a small part of a longer DNA molecule
What kind of DNA variation would you not expect to find in the human population?
Deletion of an entire chromosome
If a disease is caused by a dominant allele, it means that a person with the disease…
could be either homozygous or heterozygous for the allele
A human X-linked gene is…
found on the X chromosome
A woman who carries one recessive X-linked allele will pass the recessive allele on to…
Half of her children
Why do X-linked conditions appear more frequently in males than in females?
A male with a non functioning allele on X does not have another allele of that gene
A human X-linked gene is…..
Found on the X chromosome
What’s required for a trait that is “autosomal recessive” to be expressed phenotypically?
Two copies of the recessive allele must be inherited
An allele is dominant if….
The allele always determines the phenotype
A man who is a carrier for an autosomal allele will pass this allele on to….
Half of all his children
Both of your parents have cleft chins but you don’t. What happened? Why do you look different from your parents? In this case, cleft chin (T) is dominant; no cleft chin is recessive (t).
Both of your parents are heterozygotes (Tt and Tt)
If “cleft chin” is dominant and “no cleft chin” is recessive, what genotype is required to have “no cleft chin”? T=dominant; t=recessive
tt
About one in 400 people in the population carry mutated BRCA1 or BRCA2 genes, and more than half of women with the BRCA1 mutation will develop breast cancer before age 70. BRCA1 is found on chromosome 17, and BRCA2 is found on chromosome 13. The gametes produced by a father who is a carrier for the BRCA1 mutation will:
Carry the BRCA-1 mutation half the time
An autosomal recessive trait….
Will appear only in children of parents who both carry the gene
Two deaf individuals fall in love. Both are from Deaf families: Tim is deaf; Alesha is hearing. Both know their genetic family history–their families share the same gene for deafness. The gene is dominant. However, they don’t know their specific genotypes. If B=Deaf and b=hearing, which is true?
Alesha’s genotype is bb
Sickle-cell anemia is a common disorder that is inherited in an autosomal recessive pattern. A man and a woman who did not have Sickle-cell anemia have one healthy child and one child with Sickle-cell anemia. What is the chance that their healthy child will be a carrier of the recessive Sickle-cell anemia allele?
67% or 2/3
Red-green color blindness is an X-linked recessive trait. What is the probability that a color-blind woman and a man with color vision will have a color-blind daughter?
0%
The polymerase chain reaction (PCR) allows scientists to do all of the following EXCEPT:
Sequence the bases within a gene as it is being copied
Two DNA fragments are separated by electrophoresis in an agarose gel. How is the one that has travelled farther in the gel different from the other?
It is smaller
What DNA sequence would stick to Spot 2 with DNA strands with the sequence ATTCAG?
TAAGTC
True or false?: SNP-chip involves generating sequences of billions of short DNA fragments that are fed into software to reconstruct the sequence of the entire human genome.
False, this is not how SNP-chips work
Which genetic test would be the cheapest and yet still effective test for the variation found in fragile X? Fragile X is caused by mutations in the FMR1 gene , usually caused by a mutation in which a DNA segment, known as the CGG triplet repeat, is inserted in large numbers within the FMR1 gene.
PCR followed by gel electrophoresis is the least expensive option to determine a size difference between two mutations
If an individual only has DNA that binds to the spot containing DNA strands matching the normal allele for the HAXA gene, you can conclude that the individual tested is…
Homozygous for the normal version of the HEXA gene
If a deletion in the PTEN gene is linked to cancer, what type of PCR product would most likely have increased risk of developing cancer?
A smaller PCR product, which would migrate further in gel
Hemophilia A is caused by one of several genetic variations in the F8 gene, which codes for a protein called Factor VIII. The Factor VIII protein helps blood cells stick together to stop the flow of blood at the site of an injury. Known disease-causing variations include SNPs, insertions, and deletions. Which types of tests should be used to test for Hemophilia?
Conventional/single-gene sequencing
What is true about the most common genetic diseases?
They are complex traits that result from interaction of many genes with the environment
True or False: Pharmacogenomics can be used to determine if a patient can have a dangerous reaction to a medication?
True
Which type of inheritance is most likely to cause a bell curve of phenotypes?
Polygenic inheritance
An allele of a gene exists that increases risk for Schizophrenia by 25% or 1.25 times when this allele is inherited as a single copy. Approximately 1% of the US population exhibit symptoms of schizophrenia. Which of the options below would best represent the likelihood that an individual with this allele will develop schizophrenia?
1.25%
What is true about Genome Wide Association Studies?
They look at hundreds or thousands of SNPs at the same time in a large group of people and have been used to identify SNPs associated with complex conditions and response to drugs
Common medical problems such as heart disease, diabetes, and obesity do not have a single genetic cause. They are likely associated with the effects of multiple genes in combination with lifestyle and environmental factors. Conditions caused by many contributing factors are called…
Complex or multifactorial disorders
Complex or multifactorial traits are influenced by…
Environmental factors such as lifestyle choices
True or false: Pharmacogenomics describes the method of performing genetic tests of embryos during in vitro fertilization procedures.
False
What do Genome Wide Association Studies do?
Use SNP-ChIP or Whole-genome sequencing to test for genetic variations to determine how certain genetic variations make small contributions to a disease
What is the definition of genetic test?
Analysis of DNA to look for a genetic variation that may be associated with a specific trait, such as a disease or disorder
What is the purpose of genetic testing?
It can identify risks for many genetic diseases and results can lead to “pre-symptomatic” treatment decisions
What is genetic discrimination?
Occurs if people are treated unfairly because of differences in their DNA that increases their chances of getting a certain disease
What is an example of genetic discrimination?
A health insurer might refuse to give coverage to a woman who has a DNA difference that raises her odds of getting breast cancer, or employers could use the info to decide whether to hire or fire workers
What is included in the Genetic Information Nondiscrimination Act of 2008?
The law protects people from discrimination by health insurers and employers on the basis of DNA information
What is not included in the Genetic Information Nondiscrimination Act of 2008?
The law does not cover companies with fewer than 15 employees and does not cover life, disability, and long term care insurance
What is hypertrophic cardiomyopathy?
Genetic condition that results in thickening of the heart wall, making it more difficult for blood to leave the heart. Affects 0.1-0.2% of the world population and results in sudden death in ~1% of those with the condition
How is genetic testing related to hypertrophic cardiomyopathy?
Genetic tests now exist for this condition. Olympic policy in Italy requires all athletes must be tested and can excluded from competition on basis of results. Controversy on whether athletes should be tested surrounds this subject
