Genetics: Analysis and Principles
6th Edition
ISBN: 9781259616020
Author: Robert J. Brooker Professor Dr.
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 19, Problem 26CONQ
Achondroplasia is a rare form of dwarfism. It is caused by an autosomal dominant mutation within a single gene. Among 1,422,000 live births, the number of babies born with achondroplasia was 31. Among those 31 babies, 18 of them had one parent with achondroplasia. The remaining babies had two unaffected parents. What is the mutation frequency for this disorder among these 1,422,000 babies? What is the mutation rate for achondroplasia?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Achondroplasia is a form of dwarfism that is inherited in humans as an autosomal dominant disorder. A survey in a small country showed that, within a two-year period, there were 24 children with normal parents born with this disorder out of a total of 16,789 births. What is the mutation rate in mutations/locus/generation? answer to the nearest 0.0001.
Each of the four types of structural chromosomal mutations is illustrated below. Label each picture with the type of chromosomal mutation that has occurred.
Achondroplasia is an autosomal dominant disorder characterized by disproportionate short stature: the legs and arms of people with achondroplasia are short compared with the head and trunk. The disorder is due to a base substitution in the gene, located on the short arm of chromosome 4, that encodes fibroblast growth factor receptor 3 (FGFR3). Although achondroplasia is clearly inherited as an autosomal dominant trait, more than 80% of the people who have achondroplasia are born to parents with normal stature. This high percentage indicates that most cases are caused by newly arising mutations; these cases (not inherited from an affected parent) are referred to as sporadic. Studies have demonstrated that sporadic cases of achondroplasia are almost always caused by mutations inherited from the father (paternal mutations). In addition, the occurrence of achondroplasia is higher among the children of older fathers; approximately 50% of children with achondroplasia are born to fathers…
Chapter 19 Solutions
Genetics: Analysis and Principles
Ch. 19.1 - 1. A mutation changes a codon that specifies...Ch. 19.1 - A down promoter mutation causes the promoter of a...Ch. 19.1 - 3. A mutation in one gene that reverses the...Ch. 19.1 - Which of the following is an example of a somatic...Ch. 19.2 - Prob. 1COMQCh. 19.3 - Which of the following is not an example of a...Ch. 19.3 - A point mutation could be caused by a....Ch. 19.3 - One way that TNRE may occur involves the formation...Ch. 19.4 - Nitrous acid replaces amino groups with keto...Ch. 19.4 - Prob. 2COMQ
Ch. 19.4 - Prob. 3COMQCh. 19.5 - The function of photolyase is to repair a....Ch. 19.5 - Which of the following DNA repair systems may...Ch. 19.5 - 3. In nucleotide excision repair in E. coli, the...Ch. 19.5 - Prob. 4COMQCh. 19.5 - An advantage of translesion-replicating...Ch. 19 - Is each of the following mutations a transition,...Ch. 19 - Prob. 2CONQCh. 19 - What does a suppressor mutation suppress? What is...Ch. 19 - Prob. 4CONQCh. 19 - X-rays strike a chromosome in a living cell and...Ch. 19 - Prob. 6CONQCh. 19 - Prob. 7CONQCh. 19 - 8. A point mutation occurs in the middle of the...Ch. 19 - Prob. 9CONQCh. 19 - Prob. 10CONQCh. 19 - 11. Is a random mutation more likely to be...Ch. 19 - 12. Which of the following mutations could be...Ch. 19 - Prob. 13CONQCh. 19 - Discuss the consequences of a germ-line versus a...Ch. 19 - Prob. 15CONQCh. 19 - Explain how a mutagen can interfere with DNA...Ch. 19 - What type of mutation (transition, transversion,...Ch. 19 - Explain what happens to the sequence of DNA during...Ch. 19 - Distinguish between spontaneous and induced...Ch. 19 - Prob. 20CONQCh. 19 - Prob. 21CONQCh. 19 - Prob. 22CONQCh. 19 - Trinucleotide repeat expansions (TNREs) are...Ch. 19 - 24. With regard to TNRE, what is meant by the term...Ch. 19 - 25. What is the difference between the mutation...Ch. 19 - Achondroplasia is a rare form of dwarfism. It is...Ch. 19 - Prob. 27CONQCh. 19 - In the treatment of cancer, the basis for many...Ch. 19 - Prob. 29CONQCh. 19 - 30. Which of the following examples is likely to...Ch. 19 - Prob. 31CONQCh. 19 - Prob. 32CONQCh. 19 - Prob. 33CONQCh. 19 - With regard to the repair of double-strand breaks,...Ch. 19 - Prob. 35CONQCh. 19 - Prob. 36CONQCh. 19 - 37. Three common ways to repair changes in DNA...Ch. 19 - Prob. 38CONQCh. 19 - Prob. 39CONQCh. 19 - Explain how the technique of replica plating...Ch. 19 - 2. Outline how you would use the technique of...Ch. 19 - 3. From an experimental point of view, is it...Ch. 19 - Prob. 4EQCh. 19 - Prob. 5EQCh. 19 - 6. Richard Boyce and Paul Howard-Flanders...Ch. 19 - In E. coli, a variety of mutator strains have been...Ch. 19 - 2. Discuss the times in a person’s life when it is...Ch. 19 - A large amount of research is aimed at studying...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior history of the disease. Consider the following pedigree (the darkly colored symbols represent affected individuals): a. Circle the individual(s) in which the mutation most likely occurred. b. Is the person who is the source of the mutation affected by retinoblastoma? Justify your answer. c. Assuming that the mutant allele is fully penetrant, what is the chance that an affected individual will have an affected child?arrow_forwardAlbinism is characterized by the lack of a dark pigment called melanin in the hair, skin and eyes. Albinism is caused by the absence of an functioning enzyme called thyrosinase, which is necessary for the synthesis of melanin. Given this bit of information, what can you assume about the heredity pattern of this trait? A) It is caused by a recessive allele of the gene coding for thyrosinase. B) It is caused by a dominant allele of the gene coding for melanin. C) It is caused by a dominant allele of the gene coding for thyrosinase. D) It is caused by a recessive allele of the gene coding for melanin. E) There is not enough information here to tellarrow_forwardTay Sachs is a rare autosomal recessive disorder that causes mental and physical disabilities leading to death in infants. Affected individuals are lacking the enzyme hexosaminidase, causing lipids to build up in the brain.The HEXA gene on chromosome 15 codes for hexosaminidase, and a four base pair insertion in the gene results in an altered reading frame and non-functional enzyme being produced. Individuals who are carriers (heterozygotes) of the Tay-Sachs allele are not affected by the disease but appear to have increased protection against tuberculosis.The incidence of Tay-Sachs disease is much higher among Ashkenazi Jews originating from Eastern Europe than the general population of the United States. About 1 in 3 500 babies of Ashkenazi Jewish heritage are born with Tay-Sachs disease and about 1 in 30 Ashkenazi Jews are carriers compared to about 1 in 320 000 babies born with the disease and about 1 in 300 carriers in the general United States population. Ashkenazi Jews living in…arrow_forward
- Six months pregnant, an expectant mother had a routine ultrasound that showed that the limbs of the fetus were unusually short. Her physician suspected that the baby might have a genetic form of dwarfism called achondroplasia, an autosomal dominant trait occurring with a frequency of about 1 in 27,000 births. The parents were directed to a genetic counselor to discuss this diagnosis. In the conference, they learned that achondroplasia is caused by a mutant allele. Sometimes it is passed from one generation to another, but in 80 percent of all cases it is the result of a spontaneous mutation that arises in a gamete of one of the parents. They also learned that most children with achondroplasia have normal intelligence and a normal life span. 1. What information would be most relevant to concluding which of the two mutation origins, inherited or new, most likely pertains in this case? How does this conclusion impact on this couple’s decision to have more children? 2. It has been…arrow_forwardTwo related forms of muscular dystrophy—Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD)—are both recessive, X-linked, single-gene conditions caused by point mutations, deletions, and insertion in the dystrophin gene. Each mutated form of dystrophin is one allele. Of the two diseases, DMD is much more severe. Given your knowledge of mutations, the genetic code, and translation, propose an explanation for why the two disorders differ greatly in severity.arrow_forwardOne of the most famous cases of an X-linked recessive mutation in humans is that of hemophilia found in the descendants of Britain’s Queen Victoria. The pedigree of the royal family indicates that Victoria was heterozygous for the trait; however, her father was not affected, and no other member of her maternal line appeared to carry the mutation. What are some possible explanations of how the mutation arose? What types of mutations could lead to the disease?arrow_forward
- Gene mutations can be classified in two major ways:(1) hereditary or germline mutations that are inherited from a parent and are present throughout a person’s life in virtually every cell in the body.(2) acquired or somatic mutations that occur at some time during a person’s life and are present only in certain cells, not in every cell in the body.If there is no family history of a particular disease but a child has the disease then it may have arisen due to a(n) ________ mutation early during development. A) acquired B) inherited C) silent D) transitionarrow_forwardLeber congenital amaurosis (LCA) is a form of congenital blindness in humans and is known to be caused by homozygosity for recessive mutations in the RPE65 gene. Recently, a rare dominant mutation in RPE65 has been implicated as one cause of an eye disease called retinitis pigmentosa, which is characterized by retinal degeneration that can progress to blindness. The dominant RPE65 mutation is a missense mutation causing amino acid 447 in the polypeptide to change from Asp to Glu. Little is known about the nature of the mutant protein. a. Do you think that the dominant allele is more likely a loss-of-function or a gain-of-function mutation? Explain. b. Recently a group of clinicians and scientists reported that gene therapy (gene replacement therapy) for LCA has been at least partially successful. Do you think that the same kind of gene therapy can be used for patients with retinitis pigmentosa caused by the dominant mutant allele of RPE65? Explain.arrow_forwardLesch-Nyhan syndrome is due to a mutation in a gene that encodesa protein called hypoxanthine-guanine phosphoribosyltransferase(HPRT). HPRT is an enzyme that functions in purine metabolism.People afflicted with this syndrome have severe neurodegenerationand loss of motor control. The pedigree below contains severalindividuals with Lesch-Nyhan syndrome, shown with blacksymbols. Based on this pedigree, does this syndrome appearto be inherited by an autosomal recessive, autosomal dominant,X-linked recessive, or X-linked dominant pattern? Explainyour reasoning.arrow_forward
- Diamond–Blackfan anemia (DBA) is a rare, dominant genetic disorder characterized by bone marrow malfunction, birth defects, and a predisposition to certain cancers. Infants with DBA usually develop anemia in the first year of life, have lower than normal production of red blood cells in their bone marrow, and have a high risk of developing leukemia and bone cancer. At the molecular level, DBA is caused by mutations in any one of 10 genes that encode ribosomal proteins. The first-line therapy for DBA is steroid treatment, but more than half of affected children develop resistance to the drugs and in these cases, treatment is halted. DBA can be treated successfully with bone marrow or stem cell transplants from donors with closely matching immune system markers. Trans- plants from unrelated donors have significant levels of complications and mortality. QUESTIONS: 1. Given that a faulty ribosomal protein is the culprit and causes DBA, discuss the possible role of normal ribosomal…arrow_forwardTay–Sachs disease is caused by loss-of-function mutations ina gene on chromosome 15 that encodes a lysosomal enzyme.Tay–Sachs is inherited as an autosomal recessive condition.Among Ashkenazi Jews of Central European ancestry, about1 in 3600 children is born with the disease. What fraction ofthe individuals in this population are carriers?arrow_forwardDiamond–Blackfan anemia (DBA) is a rare, dominant genetic disorder characterized by bone marrow malfunction, birth defects, and a predisposition to certain cancers. Infants with DBA usually develop anemia in the first year of life, have lower than normal production of red blood cells in their bone marrow, and have a high risk of developing leukemia and bone cancer. At the molecular level, DBA is caused by mutations in any one of 10 genes that encode ribosomal proteins. The first-line therapy for DBA is steroid treatment, but more than half of affected children develop resistance to the drugs and in these cases, treatment is halted. DBA can be treated successfully with bone marrow or stem cell transplants from donors with closely matching immune system markers. Trans- plants from unrelated donors have significant levels of complications and mortality. 1. Given that a faulty ribosomal protein is the culprit and causes DBA, discuss the possible role of normal ribosomal proteins. Why might…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
Mitochondrial mutations; Author: Useful Genetics;https://www.youtube.com/watch?v=GvgXe-3RJeU;License: CC-BY