HEXA Gene Mutation Questions

HEXA Gene Mutation Questions

HEXA Gene Mutation Questions

Part 1 (6 marks)

Tay-Sachs disease is a metabolic disorder that is common in Ashkenazi Jewish. Infants with the disease might expressdeafness, blindness, and/or paralysis. These symptoms are due to loss of neurons as lipid is not metabolized properly which leads to its accumulation on the nerve cells, then subsequently their destructionsA nonsense mutation in HEXA gene lead to form a truncated hexosaminidase Aenzyme that is not efficient for lipid metabolism.

1) What is the molecular technology to analyze the product of HEXA gene mutation(2 marks)

2) Write the principle of this technique? (2 marks)

3) Explain the expected results of this technique if you compared a sample for a Tay-Sachs patient and a sample for normal control. (2 marks)



– Part 2 (4 marks):

After running your PCR experiment to analyze HBA1genein two patients, who are expected to have thalassemia, you got this gel result (Figure 1).

As a researcher;

1) Why you get these failed PCR results? (2 marks)

2) How would you solve this problem to get clear bands?(2 marks)

Figure 1: PCR results of HBA1 gene.

Lane 1; marker, Lane 2; patient 1 sampleLane 3; patient 2sample.

2) Bioinformatic question:

– Part 1 (5 marks):

Exploring NCBI database websites, find the following data for GAPDH gene (Attach a screenshot for the NCBI website to support your answers):

1) Gene Specific Location in Human Genome and its Exons count(2 marks)

2) List two other species with the same gene(1 mark)

3) Retrieve GAPDH gene sequence.(2 marks)

– Part 2 (5 marks):

Design a PCR primer set for GAPDH gene (Attach a screenshot for the primer design tool to support your answer):

1) Give the sequences of both forward and reverse primers(2 marks)

2) Give the details of the primer sets(3 marks)

3) Integrated molecular technology question:

– Part 1 (10 marks)

A-12-year-old boy came to the pediatric clinic showing symptoms of intellectual disability, and frequent seizures. Physically the boy showed small head and low weight. The pediatrician thought these symptoms arerelevant to Phenylketonuria. A blood sample was sent to your Molecular Laboratory for analysis and you received the case sample. How would you process the sample?

1) Give a summary about this disease; mode of inheritance, symptoms; and pathogenesis(marks)

2) Mention some mutations that cause this disease.(1mark)

3) What type of molecular technology would you run to identify the mutation causing this disease in this patient?(2 marks)

4) What type of genetic molecule do you need to extract from the blood to run this technique(1 mark)

5) Why did you select this molecular technology to analyze the sample of this case?(3 marks)

Medical Genetics Committee