Organ donors and DNA Test

Organ donation is the process by which a person donates an organ to another who is in need of an organ transplant. Chronic diseases are one of the most common reasons for organ transplants, with the kidney being the most sought after and hardest to match organ.


The organ donor can be a family member or even a stranger and there are no restrictions between age or gender, however the most important thing to keep in mind is that the donor must have a biological compatibility with the intended recipient. Compatibility is tested before donation to assess the possible rejection of the donated organ from the recipient. The higher the compatibility, the lower the chances of rejection are.


Family members have the highest chances of being compatible organ donors due to having similar genes. DNA testing with familial relations of the patient may be carried out to confirm if they are biologically related or not and to gain an idea of the compatibility level. However, compatibility tests still need to be carried out to measure the similarity, as even though they are related the human gene is unpredictable in its creations.


There are three main blood tests that are carried out to assess compatibility:


  • Blood typing will assess the donor’s and the patient’s blood type (type O,A,B)

  • Tissue typing or HLA typing (human leukocyte antigen) asses whether the antigens between donor and patient are similar as matching antibodies decrease the chances of rejection

  • Cross matching is where a sample of blood from the donor and the patient are mixed and analyzed to see if the patients cells attack the donors cells

In the exceptional cases of identical twins, the match is fully compatible as they share a 100% of their DNA. This would mean fewer chances of organ rejection and less complications. A twin test can be used to determine if a pair of twins are identical or not.