Human Genetics

DNA mutation refers to a change in the nucleotide sequence of DNA, which can occur naturally or due to external factors like radiation or chemicals. Mutations can affect a single nucleotide (point mutation) or involve larger changes like insertions, deletions, or duplications of DNA segments. There are three main types of mutations:

1. Silent mutations: Do not change the protein produced.

2. Missense mutations: Change one amino acid in the protein, potentially altering its function.

3. Nonsense mutations: Introduce a premature stop codon, resulting in a shortened protein. Mutations can lead to genetic disorders, contribute to cancer, or play a role in evolution by introducing genetic variation. While many mutations are harmful, some can be beneficial or have no impact at all.

Gene mutations are alterations in the DNA sequence of a gene that can affect the protein it produces, potentially altering its function. These mutations can either be inherited or occur spontaneously due to errors in DNA replication or external influences like chemicals, radiation, or viral infections. Gene mutations come in various forms:

1. Point mutations: A change in a single nucleotide, which can be a substitution (replacing one base with another), insertion (adding an extra base), or deletion (removing a base).

2. Frameshift mutations: Result from insertions or deletions that shift the reading frame, causing significant changes to the protein.

3. Missense mutations: A point mutation that replaces one amino acid in the protein, potentially altering its functionality.

4. Nonsense mutations: Create an early stop codon, leading to a truncated, often nonfunctional protein.