Genetic Mutations and Mechanisms

What is a mutation and how does it differ from a polymorphism?

A mutation is a change in the DNA sequence that can lead to genetic disorders, whereas a polymorphism is a common, non-pathogenic genetic variation in the population.

What is a point mutation?

A point mutation involves a change in a single nucleotide base pair in DNA, potentially leading to missense, nonsense, or silent mutations.

What is a missense mutation?

A missense mutation changes a single nucleotide, resulting in a different amino acid in the protein, which may affect its function (e.g., sickle cell anemia).

What is a nonsense mutation?

A nonsense mutation converts a codon to a stop codon, terminating protein synthesis prematurely and often resulting in a nonfunctional protein.

What is a frameshift mutation?

A frameshift mutation involves the insertion or deletion of nucleotides, altering the reading frame of the gene and potentially producing a nonfunctional protein.

What is a deletion mutation?

A deletion mutation involves the loss of a DNA segment, potentially removing essential genetic information and causing disorders like Cri-du-chat syndrome.

What is a translocation in genetics?

A translocation is the rearrangement of genetic material between non-homologous chromosomes, which can disrupt gene function and cause genetic disorders.

What is a Robertsonian translocation?

A Robertsonian translocation involves the fusion of two acrocentric chromosomes, leading to potential genetic imbalances.

What is non-disjunction and associated disorders?

Non-disjunction is the failure of chromosomes to separate properly during meiosis, leading to aneuploidies like trisomy 21 (Down syndrome) and Turner syndrome.

What is a trinucleotide repeat expansion?

A trinucleotide repeat expansion involves the abnormal increase in three-nucleotide sequences, causing disorders like Huntington’s disease and Fragile X syndrome.