Glossary of terms

Aberration

A chromosome aberration refers to a change in the DNA of an organism. This can be a deletion, insertion, duplication or inversion.

Association study

Study undertaken to assess the association between DNA variants and disease.

Copy number variation

This is described as gains and losses of pieces of chromosomal DNA sequence.

CNV specification sheet

Provides a comprehensive list of the technical specifications associated with the CNV application.

CNV quality control (QC) sheet

This details the many QC stages undertaken on each sample at each stage of the experimental process.

Deletion

A genetic aberration in which part of a chromosome or DNA sequence is absent.

De novo CNV's

De novo CNVs can be caused by genomic rearrangements such as deletions, duplications, inversions, and translocations. A de novo CNV is a CNV that has not been inherited.

Duplication

Refers to a duplication of a region of DNA.. In some cases a whole chromosome may be duplicated.

Genetic variant

A genetic variant refers to a change in part of our genomic DNA. Genetic variants have been associated with susceptibility to certain diseases e.g. increased risk of stroke, diabetes etc.

High throughput microarray service

A state-of-the-art automated oligonucleotide microarray service, giving rapid turnaround time and rigorous quality control, with a sample throughput to suit your project - from 1 to 1000s of samples per week.

Inherited CNV's

A copy number variation that is inherited from the father or the mother.

Inversion

This indicates that part of a chromosome has been clipped out, inverted and re-inserted into the chromosome.

ISCA

The International Standard Cytogenomic Array (ISCA) Consortium: a group of clinical cytogenetics laboratories committed to establishing clear aCGH format guidelines.

Ozone control

Air flow into and around a piece of equipment is controlled to ensure that ozone levels (O3) are minimised, thus avoiding dye degradation and spurious results.

Translocation

This is a chromosome abnormality and occurs when DNA
from non-homologous chromosomes are rearranged.

WTCCC

Wellcome Trust Case Control Consortium.
The Wellcome Trust Case Control Consortium (WTCCC) was established with an aim to harness the power of newly-available genotyping technologies to improve its understanding of the aetiological basis of several major causes of global disease. Over the last year the consortium has gathered genotype data for up to 500,000 sites of genome sequence variation (single nucleotide polymorphisms or SNPs) in samples ascertained for the disease phenotypes listed in Table 1. Analysis of the genome-wide association data generated has lead to the identification of many SNPs and genes showing evidence of association with disease susceptibility, some of which will be followed up in future studies (Nature. 2007;447;661-78). In addition, the Consortium has gained important insights into the technical, analytical, methodological and biological aspects of genome-wide association analysis.