CASE STUDY| Genetic dwarfism Seven months pregnant, an expectant mother was undergoing a routine ultrasound. While prior tests had been normal, this one showed that the limbs of the fetus were unusually short. The doctor suspected that the baby might have a genetic form of dwarfism called achondroplasia. He told her that the disorder was due to an autosomal dominant mutation and occurred with a frequency of about 1 in 25,000 births. The expectant mother had studied genetics in college and immediately raised several questions. How would you answer them? How could her baby have a dominantly inherited disorder if there was no history of this condition on either side of the family?

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Answer 1

Textbook Question

Chapter 14, Problem 1CS

CASE STUDY| Genetic dwarfism

Seven months pregnant, an expectant mother was undergoing a routine ultrasound. While prior tests had been normal, this one showed that the limbs of the fetus were unusually short. The doctor suspected that the baby might have a genetic form of dwarfism called achondroplasia. He told her that the disorder was due to an autosomal dominant mutation and occurred with a frequency of about 1 in 25,000 births. The expectant mother had studied genetics in college and immediately raised several questions. How would you answer them?

How could her baby have a dominantly inherited disorder if there was no history of this condition on either side of the family?

Expert Solution & Answer

Summary Introduction

To review:

The reason for the presence of autosomal dominant disorder, without any history of that disorder in the family.

Introduction

During an ultrasound of a 7-month pregnant lady, the limbs of the fetus were found to be abnormally short. It was suspected that the baby would have achondroplasia, a genetic form of dwarfism that was due to autosomal dominant mutation. Autosomal dominant disorder is a condition in which only one copy of defected or mutated gene is required to cause the disease. Achondroplasia is a rare and genetically inherited autosomal disorder. In this condition, the individual is dwarf with short stature and short limbs. It has been seen that generally, the parents of these children are normal.

Explanation of Solution

There are various possibilitiesthatcould lead to the sudden expression of a genetic condition in a newborn baby. The first possibility could be the incomplete penetrance, that is, the proportion of the people that bear the mutation and express the mutant phenotype. It could be possible one of the parents have the mutated copy but due to incomplete penetrance does not express the mutant phenotype.

Another possibility is that the new spontaneous mutation may have arisen in the newborn. The new mutation can occur in the FGFR3 gene. This mutation result in the defect in the formation of the protein, which is responsible for the bone formation.

Conclusion

Therefore, it can be concluded that it is possible to have the autosomal dominant defect even when there is no history in family due to incomplete penetrance and spontaneous mutations.

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Answer 2

Textbook Question

Chapter 14, Problem 1CS

CASE STUDY| Genetic dwarfism

Seven months pregnant, an expectant mother was undergoing a routine ultrasound. While prior tests had been normal, this one showed that the limbs of the fetus were unusually short. The doctor suspected that the baby might have a genetic form of dwarfism called achondroplasia. He told her that the disorder was due to an autosomal dominant mutation and occurred with a frequency of about 1 in 25,000 births. The expectant mother had studied genetics in college and immediately raised several questions. How would you answer them?

How could her baby have a dominantly inherited disorder if there was no history of this condition on either side of the family?

Expert Solution & Answer

Summary Introduction

To review:

The reason for the presence of autosomal dominant disorder, without any history of that disorder in the family.

Introduction

During an ultrasound of a 7-month pregnant lady, the limbs of the fetus were found to be abnormally short. It was suspected that the baby would have achondroplasia, a genetic form of dwarfism that was due to autosomal dominant mutation. Autosomal dominant disorder is a condition in which only one copy of defected or mutated gene is required to cause the disease. Achondroplasia is a rare and genetically inherited autosomal disorder. In this condition, the individual is dwarf with short stature and short limbs. It has been seen that generally, the parents of these children are normal.

Explanation of Solution

There are various possibilitiesthatcould lead to the sudden expression of a genetic condition in a newborn baby. The first possibility could be the incomplete penetrance, that is, the proportion of the people that bear the mutation and express the mutant phenotype. It could be possible one of the parents have the mutated copy but due to incomplete penetrance does not express the mutant phenotype.

Another possibility is that the new spontaneous mutation may have arisen in the newborn. The new mutation can occur in the FGFR3 gene. This mutation result in the defect in the formation of the protein, which is responsible for the bone formation.

Conclusion

Therefore, it can be concluded that it is possible to have the autosomal dominant defect even when there is no history in family due to incomplete penetrance and spontaneous mutations.

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Answer 3

Textbook Question

Chapter 14, Problem 1CS

CASE STUDY| Genetic dwarfism

Seven months pregnant, an expectant mother was undergoing a routine ultrasound. While prior tests had been normal, this one showed that the limbs of the fetus were unusually short. The doctor suspected that the baby might have a genetic form of dwarfism called achondroplasia. He told her that the disorder was due to an autosomal dominant mutation and occurred with a frequency of about 1 in 25,000 births. The expectant mother had studied genetics in college and immediately raised several questions. How would you answer them?

How could her baby have a dominantly inherited disorder if there was no history of this condition on either side of the family?

Expert Solution & Answer

Summary Introduction

To review:

The reason for the presence of autosomal dominant disorder, without any history of that disorder in the family.

Introduction

During an ultrasound of a 7-month pregnant lady, the limbs of the fetus were found to be abnormally short. It was suspected that the baby would have achondroplasia, a genetic form of dwarfism that was due to autosomal dominant mutation. Autosomal dominant disorder is a condition in which only one copy of defected or mutated gene is required to cause the disease. Achondroplasia is a rare and genetically inherited autosomal disorder. In this condition, the individual is dwarf with short stature and short limbs. It has been seen that generally, the parents of these children are normal.

Explanation of Solution

There are various possibilitiesthatcould lead to the sudden expression of a genetic condition in a newborn baby. The first possibility could be the incomplete penetrance, that is, the proportion of the people that bear the mutation and express the mutant phenotype. It could be possible one of the parents have the mutated copy but due to incomplete penetrance does not express the mutant phenotype.

Another possibility is that the new spontaneous mutation may have arisen in the newborn. The new mutation can occur in the FGFR3 gene. This mutation result in the defect in the formation of the protein, which is responsible for the bone formation.

Conclusion

Therefore, it can be concluded that it is possible to have the autosomal dominant defect even when there is no history in family due to incomplete penetrance and spontaneous mutations.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 4

Textbook Question

Chapter 14, Problem 1CS

CASE STUDY| Genetic dwarfism

Seven months pregnant, an expectant mother was undergoing a routine ultrasound. While prior tests had been normal, this one showed that the limbs of the fetus were unusually short. The doctor suspected that the baby might have a genetic form of dwarfism called achondroplasia. He told her that the disorder was due to an autosomal dominant mutation and occurred with a frequency of about 1 in 25,000 births. The expectant mother had studied genetics in college and immediately raised several questions. How would you answer them?

How could her baby have a dominantly inherited disorder if there was no history of this condition on either side of the family?

Expert Solution & Answer

Summary Introduction

To review:

The reason for the presence of autosomal dominant disorder, without any history of that disorder in the family.

Introduction

During an ultrasound of a 7-month pregnant lady, the limbs of the fetus were found to be abnormally short. It was suspected that the baby would have achondroplasia, a genetic form of dwarfism that was due to autosomal dominant mutation. Autosomal dominant disorder is a condition in which only one copy of defected or mutated gene is required to cause the disease. Achondroplasia is a rare and genetically inherited autosomal disorder. In this condition, the individual is dwarf with short stature and short limbs. It has been seen that generally, the parents of these children are normal.

Explanation of Solution

There are various possibilitiesthatcould lead to the sudden expression of a genetic condition in a newborn baby. The first possibility could be the incomplete penetrance, that is, the proportion of the people that bear the mutation and express the mutant phenotype. It could be possible one of the parents have the mutated copy but due to incomplete penetrance does not express the mutant phenotype.

Another possibility is that the new spontaneous mutation may have arisen in the newborn. The new mutation can occur in the FGFR3 gene. This mutation result in the defect in the formation of the protein, which is responsible for the bone formation.

Conclusion

Therefore, it can be concluded that it is possible to have the autosomal dominant defect even when there is no history in family due to incomplete penetrance and spontaneous mutations.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 5

Textbook Question

Answer 6

Textbook Question

Answer 7

Expert Solution & Answer

Summary Introduction

To review:

The reason for the presence of autosomal dominant disorder, without any history of that disorder in the family.

Introduction

During an ultrasound of a 7-month pregnant lady, the limbs of the fetus were found to be abnormally short. It was suspected that the baby would have achondroplasia, a genetic form of dwarfism that was due to autosomal dominant mutation. Autosomal dominant disorder is a condition in which only one copy of defected or mutated gene is required to cause the disease. Achondroplasia is a rare and genetically inherited autosomal disorder. In this condition, the individual is dwarf with short stature and short limbs. It has been seen that generally, the parents of these children are normal.

Explanation of Solution

There are various possibilitiesthatcould lead to the sudden expression of a genetic condition in a newborn baby. The first possibility could be the incomplete penetrance, that is, the proportion of the people that bear the mutation and express the mutant phenotype. It could be possible one of the parents have the mutated copy but due to incomplete penetrance does not express the mutant phenotype.

Another possibility is that the new spontaneous mutation may have arisen in the newborn. The new mutation can occur in the FGFR3 gene. This mutation result in the defect in the formation of the protein, which is responsible for the bone formation.

Conclusion

Therefore, it can be concluded that it is possible to have the autosomal dominant defect even when there is no history in family due to incomplete penetrance and spontaneous mutations.

Answer 8

Expert Solution & Answer

Summary Introduction

To review:

The reason for the presence of autosomal dominant disorder, without any history of that disorder in the family.

Introduction

During an ultrasound of a 7-month pregnant lady, the limbs of the fetus were found to be abnormally short. It was suspected that the baby would have achondroplasia, a genetic form of dwarfism that was due to autosomal dominant mutation. Autosomal dominant disorder is a condition in which only one copy of defected or mutated gene is required to cause the disease. Achondroplasia is a rare and genetically inherited autosomal disorder. In this condition, the individual is dwarf with short stature and short limbs. It has been seen that generally, the parents of these children are normal.

Explanation of Solution

There are various possibilitiesthatcould lead to the sudden expression of a genetic condition in a newborn baby. The first possibility could be the incomplete penetrance, that is, the proportion of the people that bear the mutation and express the mutant phenotype. It could be possible one of the parents have the mutated copy but due to incomplete penetrance does not express the mutant phenotype.

Another possibility is that the new spontaneous mutation may have arisen in the newborn. The new mutation can occur in the FGFR3 gene. This mutation result in the defect in the formation of the protein, which is responsible for the bone formation.

Conclusion

Therefore, it can be concluded that it is possible to have the autosomal dominant defect even when there is no history in family due to incomplete penetrance and spontaneous mutations.

Answer 9

Expert Solution & Answer

Answer 10

Expert Solution & Answer

Answer 11

Summary Introduction

To review:

The reason for the presence of autosomal dominant disorder, without any history of that disorder in the family.

Introduction

During an ultrasound of a 7-month pregnant lady, the limbs of the fetus were found to be abnormally short. It was suspected that the baby would have achondroplasia, a genetic form of dwarfism that was due to autosomal dominant mutation. Autosomal dominant disorder is a condition in which only one copy of defected or mutated gene is required to cause the disease. Achondroplasia is a rare and genetically inherited autosomal disorder. In this condition, the individual is dwarf with short stature and short limbs. It has been seen that generally, the parents of these children are normal.

Answer 12

Explanation of Solution

There are various possibilitiesthatcould lead to the sudden expression of a genetic condition in a newborn baby. The first possibility could be the incomplete penetrance, that is, the proportion of the people that bear the mutation and express the mutant phenotype. It could be possible one of the parents have the mutated copy but due to incomplete penetrance does not express the mutant phenotype.

Another possibility is that the new spontaneous mutation may have arisen in the newborn. The new mutation can occur in the FGFR3 gene. This mutation result in the defect in the formation of the protein, which is responsible for the bone formation.

Answer 13

Conclusion

Therefore, it can be concluded that it is possible to have the autosomal dominant defect even when there is no history in family due to incomplete penetrance and spontaneous mutations.

Answer 14

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