
CASE STUDY | Timing is everything
A man in his early 20s received chemotherapy and radiotherapy as treatment every 60 days for Hodgkin disease. After unsuccessful attempts to have children, he had his sperm examined at a fertility clinic, upon which multiple chromosomal irregularities were discovered. When examined within 5 days of a treatment, extra chromosomes were often present or one or more chromosomes were completely absent. However, such irregularities were not observed at day 38 or thereafter.
How might a geneticist explain the time-related differences in chromosomal irregularities?

Case summary:
A male, who suffers from Hodgkin disease receive chemotherapy and radiotherapy treatment every 60 days. His age is in the early 20s and his attempts to have children are unsuccessful. The reason is chromosomal irregularities, which is prominent when he is examined during the first 5 days of treatment.
Characters of the case:
A male patient.
Adequate information:
Hodgkin's disease is a type of cancer which affects lymphatic system and treatment includes radiotherapy and chemotherapy.
To determine:
The time-related chromosomal irregularities during chemotherapy and radiotherapy treatment in a patient suffering from Hodgkin disease.
Explanation of Solution
Given information:
The chromosomal irregularities are not found when examined on or after 38 days of treatment.
The sperm or gamete produced when the person is under treatment is infertile as chemotherapy and radiotherapy can affect healthy cells. The process of meiosis which produces four gametes (sperms) with a haploid number of chromosomes is affected because of high exposure to chemotherapeutic drugs and radiations given during treatment.
Meiosis is the cell division which takes place in germ-line cells which is a layer of undifferentiated cells called spermatogonium present in testes (male reproductive organ). Meiosis produces four haploid gametes or sperms from diploid germ cell which becomes primary spermatocyte to undergo first meiotic division. The product of this division is called secondary spermatocyte which undergoes a second meiotic division to produce spermatids. Spermiogenesis is a specialized process which gives rise to motile sperm with a haploid number of chromosomes.
Sperm produced during the first days of treatment have chromosomal irregularities which include the presence of extra chromosomes or absence of certain chromosomes as the dosage of chemotherapy and radiotherapy affects the germ-line cell division. But at day 38 or thereafter, the dosage level reduces which may not have a direct effect on germ-line cell division. Therefore, chromosomal irregularities are based on the level of exposure to the radiation and chemotherapeutic drugs.
Thus, it can be concluded that the chromosomal irregularities are high during the initial days of treatment as the exposure is high but the level of exposure reduces after 38 days.
Want to see more full solutions like this?
Chapter 2 Solutions
Essentials of Genetics (9th Edition) - Standalone book
- This entire structure using lifecycle terminology is called what? megastrobilus microstrobilus megasporophyll microsporophyll microsporangium megasporangium none of thesearrow_forwardHow much protein should Sarah add to her diet if she gets pregnant? Sarah's protein requirements during pregnancy would be higher. See Hint B2. During calculations, use numbers rounded to the first decimal place. In your answer, round the number of grams to the nearest whole number. _______ g ?arrow_forwardC MasteringHealth MasteringNu X session.healthandnutrition-mastering.pearson.com/myct/itemView?assignment ProblemID=17396422&attemptNo=1&offset=prevarrow_forwardMost people, even those who exercise regularly at low to average intensity (1 hour at the gym or a 2- to 3-mile walk several times per week), do not need an increased protein intake. What would be the protein needs of a man named Josh who exercises moderately and is the same age and size as Wayne? Josh is 5 ft, 8 in tall and weighs 183 lb. Round the number of grams to the nearest whole number. During calculations, use numbers rounded to the first decimal place. Because protein requirement is a range, please enter two numbers: lower and upper range values, respectively. Separate the lower and upper range values, in that order, by a comma. ___, ___ g ?arrow_forwardC MasteringHealth MasteringNu X session.healthandnutrition-mastering.pearson.com/myct/itemView?assignment ProblemID=17396422&attemptNo=1&offset=prevarrow_forwardIf left untreated, most HIV-infected individuals will develop AIDS. Current treatments are focused on highlyactive antiretroviral therapy (HAART). HAART usually consists of an orally delivered drug cocktail containingtwo different reverse transcriptase inhibitors and one other drug, such as a protease inhibitor. Question: Develop a pharmacokinetic model of HAART treatment. Consider all 3 drugs. Make sure to include adiagram that illustrates your thinking, state all assumptions, and define your variables. Whatparameters would you need to know to find the concentration of drug in the plasma? In the T cells?(You do not need to write out or solve any equations.)arrow_forwardnot use ai pleseaarrow_forward(A) 25 20 20 15 NPP (Mg C/ha/yr) 10 10 5 0 0 2,000 4,000 6,000 ECOLOGY 4e, Figure 20.11 (Part 1) 2017 Sinauer Associates, Inc. Average annual precipitation (mm) 8,000arrow_forwardexplain the cascade of events (starting with relaxing trade winds) that occurs during El Niño in the eastern Pacific (off the coasts of California/North America and Peru/South America) and which lead to food-chain collapse - start with changes in the physical/oceanographic conditions, andthen systematically describe the cascading effects at each level of the food chain -arrow_forward3) Which statement(s) about the Pacific Decadal Oscillation (PDO) is/are TRUE? CIRCLE ALL THAT APPLY. A. It is a major driver of salmon populations in the Pacific B. It affects sea surface temperatures in the eastern Pacific C. Its cycles typically do not last as long as those of ENSO D. Evidence that it has occurred over many centuries has been gathered from tree ring dataarrow_forward4.arrow_forward2arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_iosRecommended textbooks for you
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningBiology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781337408332Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage Learning
- Biology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781305073951Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage LearningBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781938168130Author:Kelly A. Young, James A. Wise, Peter DeSaix, Dean H. Kruse, Brandon Poe, Eddie Johnson, Jody E. Johnson, Oksana Korol, J. Gordon Betts, Mark WomblePublisher:OpenStax College
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningBiology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781337408332Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage LearningBiology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781305073951Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage LearningBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781938168130Author:Kelly A. Young, James A. Wise, Peter DeSaix, Dean H. Kruse, Brandon Poe, Eddie Johnson, Jody E. Johnson, Oksana Korol, J. Gordon Betts, Mark WomblePublisher:OpenStax College