Genetic screening: What is karyomapping?

karyomapping

As you learn a little more about the services we offer at CRGH, you may hear something about karyomapping and wonder what that is, exactly.

We’re very excited to be able to offer this new technique to our fertility treatment patients! Karyomapping is an amazing breakthrough as far as genetic screenings go because it is quick, simple, and allows potential parents that are known to be carriers of an inherited condition the chance to avoid passing that disorder or illness down to their children.

Karyomapping is ideal for a number of people. Couples that already have an affected child, those that already know their family history of a particular disorder, and those that have had their DNA tested to confirm the presence of a defective gene are all good candidates for this technique. Through karyomapping, embryos are screened before implantation in the uterus, a practice called preimplanation genetic diagnosis (PGD).

When couples come to CRGH for fertility treatments, which often involve in vitro fertilisation (IVF), karyomapping and PGD is highly recommended because it helps reduce the chance that a foetus will be affected by a particular genetic disorder and will reduce the risk of miscarriage or failed implantation. In other words, it is linked to more babies!

Karyomapping has a much more generalised application than our highly specialised PGD efforts, which typically look for a specific mutation. With karyomapping, the scope is much broader because it is tracking affected genes throughout a family and can identify more than one inherited condition. Additionally, it will also identify any chromosomal abnormalities that may be present.

The whole procedure is simple – we’ll take a blood sample or cheek swab from the potential parents as well as any relevant relatives. Relevant relatives may be the couple’s parents or perhaps a child they have that already has a particular disorder. The test looks at about 300,000 different points and finds a ‘fingerprint’ that is unique to chromosomes that carry defective genes. This helps doctors identify those embryos that are more likely to develop into babies with genetic disorders or may have less of a chance of implanting and being carried to term.

It is important to understand that CRGH has an exclusive contract with NHS England to carry out such genetic testing and is fully licensed through the Human Fertilisation and Embryology Authority (HFEA). It is also important to understand that karyomapping and PGD are nothing more than genetic screenings, for diagnostic purposes only – we never alter or change genes.