For your better understanding of gene variants

Abstract

Genes are involved in most human diseases, and a certain understanding of genetic changes or variants is required for clinicians. Here, we have outlined the disease caused by a single gene variant as an example to deepen the understanding of gene variants. Previously, polymorphisms and mutations were distinguished from each other with a frequency of 1%; however, the boundary is not clear, and the term “variant” is now used. A variant is a concept that involves polymorphisms and mutations. Types of variants include substitutions or deletions at the DNA level, and missenses, nonsenses, or frameshifts at the protein level. Variants are written according to the Human Genome Variation Society (HGVS) nomenclature. Variants range from pathologic to non-pathologic depending on whether the protein function is altered, thus causing the disease. Websites such as GeneCards, MutationTaster, gnomAD, and ClinVar are useful in obtaining information on genes and variants. Familiarity in browsing and using these sites, obtaining the required information, and gaining a better understanding of variants will help us better understand the many hereditary disorders found in otolaryngology clinical practice.