Question

What type of gain-of-function mutation is associated with EOE, and in which gene?

a) Missense mutation in EGFR
b) Frameshift mutation in TP53
c) Nonsense mutation in BRAF
d) Duplication mutation in KRAS

Answer 1

A missense mutation in the EGFR gene is the type of gain-of-function mutation associated with EOE. This mutation results in an amino acid change in the EGFR protein, affecting cell signaling pathways and potentially increasing the activity of the protein.

Step-by-step explanation:

The type of gain-of-function mutation associated with eosinophilic esophagitis (EOE) is a missense mutation in the EGFR gene. This type of mutation leads to a single amino acid change in the protein encoded by the gene, which can have a variety of effects depending on the new amino acid and its location in the protein. In the case of EOE, the mutation can potentially increase the activity of the EGFR protein, leading to altered signaling pathways within the cell.

Additionally, a missense mutation is different from other types of mutations such as nonsense mutations, which introduce a premature stop codon and often result in nonfunctional proteins. Frameshift mutations, resulting from insertions or deletions that are not multiples of three, change the reading frame of the gene and typically produce nonfunctional proteins as well. Duplication mutations can lead to unregulated phosphorylation cascades, particularly in the context of oncogenes like KRAS.