1- Mutation in fibroblast growth factor receptor 3 (FGFR3)?
2- Abnormal binding of gene product to GAPDH (enzyme involved in glycolysis)?
3- Phosphorylation of gene product by cyclin-dependent kinases (CDK); binding of gene product to transcription factors such as E2F?
4- Mutations in fibrillin gene?
5- Which of the following could produce an XY female?
6- Which of the following is not a characteristic of cystic fibrosis?
7- Each of the following chromosome abnormalities involves a 20 megabase region of the long arm of chromosome 5 (5q). Which abnormality is most likely to cause severe disease?
8- Which of the following diseases is a good example of locus heterogeneity?
9- Why are some autosomal dominant disorders (e.g., Marfan syndrome) seen more commonly in the offspring of older fathers?
10- A woman with phenotypically normal parents has two brothers with Duchenne muscular dystrophy. She experiences mild muscle weakness in her legs. Which of the following mechanisms is most likely to be directly involved?
11- Consider a fetus affected with one of the following conditions. For which condition is spontaneous loss during pregnancy most likely?
1- In some African populations, the prevalence of sickle cell disease, an autosomal recessive condition, is 1/100. Based on this value, what proportion of the population would be heterozygous carriers of the sickle cell disease gene?.
2- If an X-linked dominant disorder affects 1/100 males in a population, what is the gene frequency for the disorder in the population?.
3- In the population in question 2 (an X-linked dominant disorder affects 1/100 males in a population), what proportion of females would be affected with the X-linked dominant disorder?.
4- A man who is affected with hemophilia A (X-linked recessive) mates with a woman who is a heterozygous carrier of this disorder. What proportion of this couple's daughters will be affected, and what proportion of the daughters will be carriers?.
5- A man who has Neurofibromatosis type 1 (autosomal dominant) marries a phenotypically normal woman. If they have five children, what is the probability that none of the children will be affected with this disorder? What is the probability that all of the children will be affected?.
6- You have ascertained a fully penetrant autosomal dominant disease condition in three offspring of a couple with no family history of the disorder. What is the most likely explanation for the pedigree shown here?.
7- In the accompanying pedigree, a man is a known heterozygous carrier for an autosomal recessive disease gene that has 60% penetrance in affected homozygotes. If he marries his second cousin, what is the probability that their offspring will be affected with the disorder (i.e., that they will manifest the disease phenotype)?
8- Name at least two features you would use to distinguish an autosomal dominant pedigree from an X-linked recessive pedigree..
9- It has been observed that missense mutations in the fibrillin 1 gene on chromosome 15 often produce more severe presentations of Marfan syndrome than do nonsense mutations in the same gene. Explain this (4-5 sentences should suffice).
10- Explain the relationship between trinucleotide repeats and anticipation. Use at least two disease examples to illustrate your points..
11- Match the pedigree with the most likely mode of inheritance. Note that complicating factors, such as reduced penetrance, may be present. Assume that the gene frequency of the disorder in the general population is very low. These answers may be used more than once.?
12- Match the pedigree with the most likely mode of inheritance. Note that complicating factors, such as reduced penetrance, may be present. Assume that the gene frequency of the disorder in the general population is very low. These answers may be used more than once?
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