Genetic polymorphisms, also known as genetic variations or genetic variants, are differences in the DNA sequence among individuals in a population.
Key types:
Single Nucleotide Polymorphisms (SNPs): These polymorphisms involve a single base-pair change in the DNA sequence. For example, at a specific position in a gene, one person’s DNA might have an “A,” while another person’s DNA at the same position has a “G.”
Insertions and Deletions (Indels): These polymorphisms involve the insertion or deletion of a small segment of DNA. Indels can cause frame shifts in a gene, potentially leading to altered protein function.
Copy Number Variations (CNVs): These polymorphisms involve the duplication or deletion of larger DNA segments, ranging from a few hundred base pairs to several megabases.
Chromosomal Rearrangements: These polymorphisms involve more extensive structural changes in chromosomes, such as translocations, inversions, and deletions or duplications of entire genes or chromosomal segments.
Key considerations:
Functional Consequences: Many genetic polymorphisms have functional consequences. They can affect gene expression, protein structure and function, traits, and disease susceptibilities.
Pharmacogenetics: Genetic polymorphisms play a role in how individuals respond to medications.
Genetic testing: Genetic testing, including direct-to-consumer genetic testing, is increasingly popular for assessing individual genetic polymorphisms.