Which of the following are examples of genomic imprinting? 1. Angelman syndrome 2. Williams syndrome 3. Prader-Willi syndrome 4. DiGeorge syndrome Select the correct answer using the code given below:
To answer the question about genomic imprinting and the associated syndromes, we need to understand what genomic imprinting is and identify which syndromes are related to it.
Genomic Imprinting: It is an epigenetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner. If the allele of a gene inherited from the father is imprinted, then only the allele from the mother is expressed, and vice versa.
We look at each of the options to determine if they are related to genomic imprinting:
- Angelman Syndrome: This syndrome is a classic example of genomic imprinting. It is caused by the absence of maternally inherited genetic material at chromosome 15q11-q13, while the paternal copy is silenced due to imprinting.
- Williams Syndrome: This syndrome is not caused by genomic imprinting. It is due to a deletion of genetic material from a specific region of chromosome 7.
- Prader-Willi Syndrome: This syndrome is also a consequence of genomic imprinting. It is caused by the absence of paternal genetic material at chromosome 15q11-q13, with the maternal allele being imprinted.
- DiGeorge Syndrome: This syndrome is not a result of genomic imprinting. It is caused by the deletion of a small segment of chromosome 22.
Based on this analysis, the syndromes related to genomic imprinting are:
- Angelman Syndrome
- Prader-Willi Syndrome
Therefore, the correct answer is: 1 and 3.
Important Questions from Congenital Disorders
- To prevent recurrence, expectant mothers with a previous fetus with neural tube defect should receive folic acid daily at the dose of :
Consider the following statements regarding non-invasive prenatal screening (NIPS) for screening high risk pregnancies for aneuploidies:
1. It is carried out on maternal blood.
2. It is done before 10 weeks gestation.
3. It has a negative predictive value of about 98%.
4. Invasive testing is needed for confirmation of a positive test.
Which of the statements given above are correct?
- The risk of Down syndrome is 100% in the offspring, if:
- To reduce the risk of neural tube defects in the baby, which of the following are recommended?
- A tall thin adolescent boy is found to have gynaecomastia and small testes. His blood testosterone level is undetectable, and serum FSH and LH levels are elevated. Which one of the following is the likely karyotype pattern?
