Question

Please answer this question:

1.

A patient has a genetic disease and pays for exome sequencing in an attempt to identify the genetic polymorphism leading to the disease. all isolated exome sequences are identical when compared to a reference genome. what type of mutations may explain why no polymorphisms are identified?

a. the mutation is an enhancer

b. the mutation is in a repressor

c. the mutation is a deletion encompassing an exon

d. A and B only

Answer 1

Answer: Option D is correct.

Explanation:

Mutations can be found in coding as well as noncoding regions of the genome.

Coding regions = Exons

Non-coding regions = Introns and other cis elements such as promoter, enhancer or silencer

Mutations in non-coding regions can affect gene expression. For example, a mutation in the promoter region can lead to no expression of the gene. A mutation in silencer can lead to overexpression of a gene.

In the given case, the genetic disease could be due to a mutation in the non-coding regions as there was no mutation identified in the exome.