geenivariantti

geenivariantti, also known as a gene variant, refers to a difference in the DNA sequence of a particular gene when compared to a reference sequence. These variations can be as small as a single nucleotide polymorphism (SNP), involve insertions or deletions (indels), or encompass larger structural changes such as copy number variations or chromosomal rearrangements. Gene variants are inherited from parents and can also arise de novo during development.

The bulk of identified gene variants are considered benign, meaning they have no discernible effect on an individual's health or phenotype. However, a subset is pathogenic or likely pathogenic, contributing to disease susceptibility or manifestation. Modern genomic sequencing technologies, including whole-genome sequencing and targeted gene panels, enable thorough cataloguing of variants in both research and clinical settings. Databases such as ClinVar, dbSNP, and gnomAD compile variant information, providing allele frequency data and clinical significance reviews.

From an evolutionary perspective, gene variants generate genetic diversity that fuels adaptation and speciation. In medicine, the identification of pathogenic variants informs diagnosis, prognosis, and therapeutic decision-making, particularly in the era of precision medicine. The classification of variants follows guidelines that assess factors such as population frequency, computational predictions, segregation analysis, functional studies, and literature evidence. Ongoing efforts in genomics aim to improve variant interpretation accuracy, reduce uncertainty, and expand our understanding of gene-disease relationships.