The science of genetic testing


DNA (DeoxyriboNucleic Acid) is the molecule that carries the genetic information in almost all forms of life. It is made up of 2 long chains of nucleotides (a nucleotide being a unit composed of a Nitrogen base, a suger ring and a phosphate molecule). The 2 chains are wrapped around each other and are joined across the nitrogen bases to form a helix. Imagine a spiral staircase with the joined nitrogen bases being the treads

The DNA is tightly packed into structures called Chromosomes. Humans have 23 so-called autosomal chromosomes together with 2 sex chromosomes (2 X chromosomes for females and an X and Y chromosome for males). In embryos, not having the correct number of chromosomes has been linked to increased rates of miscarriage and other genetic problems when children are born. Further information on chromosome testing can be found on our PGT-A page.

Genes are made of specific blocks of nucleotides and are responsible for making specific proteins. Gene defects may lead to over or underproduction of vital proteins that give rise to a disease or syndrome. Further information on testing for gene disorders can be found on our PGT-M page