A certain couple has six children – four boys (ages 2yr, 5yrs, 9yrs and 11yrs old) and two girls (ages 5yrs and 7yrs old). The oldest boy shows the symptoms of Duchenne Muscular Dystrophy (DMD). You are a geneticist and they come to you for advice. What would you tell them about the chances of their other children developing the disease?

A certain couple has six children – four boys (ages 2yr, 5yrs, 9yrs and 11yrs old) and two girls (ages 5yrs and 7yrs old). The oldest boy shows the symptoms of Duchenne Muscular Dystrophy (DMD). You are a geneticist and they come to you for advice. What would you tell them about the chances of their other children developing the disease?

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter16: Reproductive Technology, Genetic Testing, And Gene Therapy

Section: Chapter Questions

Problem 16QP: A couple has had a child born with neurofibromatosis. They come to your genetic counseling office...

See similar textbooks

Similar questions

In man, muscular dystrophy is a condition in which the muscles waste away during early life and may result in a shorter life expectancy. It is due to a sex-linked, recessive gene. A certain couple has five children – three boys (ages 1yr, 3yrs, and 10yrs old) and two girls (ages 5yrs and 7yrs old). The oldest boy shows the symptoms of this disease. You are their family physician and they come to you for advice. What would you tell them about the chances of their other children developing the disease?
A couple is planning a family, but since each has a brother having the sickle-cell disorder, they are worried that their kids might develop the disorder too. Neither of them nor their respective parents have the disorder. Which of the following will be your smartest advice as a genetic counsellor? One of four of their children can be expected to have sickle cell. It is possible that none of their kids will have the disorder, but tests should be carried out on both of them to confirm. All of their children will have sickle-cell disorder. There is no chance of any of their kids having sickle cell.
A couple, who are both normal, have a daughter who is albino and a son who is normal. a) what is the probability that their normal son is a carrier of the albinism gene? Show your work. b) the couple wants to have 3 more children; what is the probability that they will have 3 normal girls? Show your work.
K.S. comes for a clinic visit to determine whether she is pregnant. She is very concerned because she suspects there may be a genetic disease in her family. On further questioning, you find out that her brother’s son has the disorder. Her brother’s other children (a boy and a girl) are unaffected. K.S.’s parents, grandparents, and other siblings (a brother and two sisters) do not have manifestations of the disorder. Her brother’s wife has said that she thinks one of her distant relatives may have had the disease. Discussion Questions If the disorder is indeed inherited as a single-gene defect, do you think it is autosomal dominant, autosomal recessive, or X linked? Justify your answer. Construct a pedigree chart and predict the likelihood that K.S. has the defective gene.
Cystic Fibrosis (CF) is an autosomal recessive condition. Therefore, heterozygous (Cc) carriers do not display symptoms. Two parents who are carriers plan to start a family and you are a genetic counselor helping to advise them about their chances of having children affected by CF. a) Suppose the couple has 4 children, each one year apart. What is the probability that all 4 children will inherit CF? b) What is the probability that any 3 of their 4 children will not inherit CF, but 1 will be affected? c) What is the probability that their first child will not inherit CF, but the younger 3 children will inherit CF?
A woman knows that her mother is a carrier of Kartagener’s syndrome (an autosomal recessive disorder). The woman does not know if either she or her husband are carriers. The couple wants to have a child, but is worried about whether or not they could have a child with Kartagener’s syndrome. Should the couple seek the advice of a genetic counselor? In other words, is there a chance they could have an affected child? If there is a chance, please make sure your answer includes the specific parental genotypes necessary to make this possible.
Clara has polydactyly, an autosomal dominant that is 80% penetrant. Clara inherited her polydactyly from her mother, her father had no polydactyly in his family. She has an extra toe on her left foot. Her husband Ralph has no polydactyly in his family. A) What is the chance that Clara will have a child that will inherit polydactyly? B) What is the chance that the child will express polydactyly. You can leave these as un-calculated equations.
You met with two parents whose first child has sickle cell anemia. (The parents show no signs of the disease themselves). The mother comes to you in the third month of her second pregnancy, and wants to know if this child will also inherit the disease. As a genetics counselor, you are ready to evaluate this couple’s case by doing the following:1. Determine what the genotype of each parent is. Is this disease autosomal or sex-linked? Dominant or recessive?
Tuberous Sclerosis (TS) is an autosomal dominant genetic disease characterized by seizures, mental retardation, autism, and benign tumors of the brain, heart, skin, and kidneys. The kidney tumors can also be malignant. This disease exhibits a wide range of severity, and only about 1/3 of the cases are inherited. Two different genes have been tightly linked to the disease in families where it is inherited. The remaining 2/3 appear to be due to mutations in one of the 2 genes as well. Overall it appears that 1/2 are caused by mutations in TSC1 and the other half by mutations in TSC2. A rat model for hereditary renal carcinoma (kidney cancer) has been found. Southern and Northern blot analysis of the TSC1 and TSC2 gene revealed no differences between these rats and normal rats. Not all the rats in the strain would get cancer but a significant proportion did and those were selected for and used in experiments. 1. a) What was detected by the Southern blots? (look this up, make your…
A young lady requested pre-marital genetic counselling because her sister had died in infancy of gangliosidosis, an autosomal recessive disease. What is the risk that this young lady has similarly affected offspring? What advice should be given?
Another couple is concerned their child will be born with sickle cell anemia. The woman does not have sickle cell anemia. The woman’s mother had sickle cell anemia and her father was a carrier of the sickle cell gene. The man knows that he is not a carrier of the sickle cell gene. What is the probability that the child will be a carrier of sickle cell anemia?
Phenylketonuria (PKU) is a human hereditary disease resulting from the inability of the body to process the chemical phenylalanine, which is contained in the protein we eat. PKU is manifest in early infancy and, if it remains untreated, generally leads to cognitive impairment. PKU is caused by a recessive allele with simple Mendelian inheritance. A couple intends to have children but consults a genetic counselor because the man has a sister with PKU and the woman has a brother with PKU. There are no other known cases in their families. They ask the genetic counselor to determine the probability that their first child will have PKU. What is this probability?