[Structural variation in the human genome contributes to variation of traits]

Abstract

Background: The human genome contains a large number of single nucleotide polymorphisms (SNPs) that contribute to normal variation of human traits. Many SNPs have also been shown to affect the development and predisposition of disease. Comparisons of genomes have recently shown that also large DNA segments can vary in structure and number of copies between individuals. A large number of duplications, deletions and inversions has been detected, ranging in size from a few thousand to several millions base pairs. Here we describe the structural variations detected in the human genome, their impact on normal phenotypic variation in the population, and how differences in genome structure may contribute to development of disease.

Material and methods: This article is based on studies of literature retrieved through a non-systematic search of PubMed.

Results and interpretation: Many structural variations in the genome overlap with genes. Duplications and deletions may change the copy number of genes, and inversions may disrupt gene structure. Some of the affected genes contribute to phenotypic variation between healthy individuals, while others can predispose to disease or contribute to disease development. Diseases caused by such structural variations constitute a major health problem in the population.