Frame-Shift Mutation

Introduction

• Frame-shift mutations are a type of genetic mutation caused by insertions or deletions of nucleotides within a DNA sequence.
• These mutations disrupt the reading frame during translation, leading to significant changes in the resulting protein.

Insertions and Deletions

• Frame-shift mutations occur due to insertions (addition) or deletions (removal) of one or more nucleotides in a DNA sequence.
• These mutations shift the reading frame by altering the grouping of codons during protein synthesis.

Impact of Frame-Shift Mutations

• When nucleotides are inserted or deleted, the codon reading frame is shifted by one or more positions.
• This shift changes the way codons are read during translation, resulting in the following effects:
  • Altered Amino Acid Sequence: The changed reading frame leads to different codons being read, which codes for entirely different amino acids.
  • Non-Functional Proteins: The resulting protein is usually non-functional or severely impaired in its function.
  • Loss of Protein Structure: Frame-shift mutations can disrupt the normal folding of the protein, further affecting its function.

---

Frame-Shift Mutation

Consequences of Frame-Shift Mutations

• Frame-shift mutations have more pronounced effects compared to point mutations.
• They often result in non-viable proteins that cannot perform their intended biological roles.
• These mutations can lead to genetic disorders and diseases when they occur in critical genes.

Causes of Frame-Shift Mutations

Frame-shift mutations can be caused by various factors, including:

• Spontaneous mutations: Errors during DNA replication or repair.
• Induced mutations: Exposure to mutagenic agents like radiation or certain chemicals.