• Question: how does a genetic deformity happen?

    Asked by 925genm52 to Yinka, Stéphane, Matt, Juhi, Gemma, David on 13 Mar 2018.
    • Photo: David Howard

      David Howard answered on 13 Mar 2018:

      A genetic deformity is the result of an error in our genetic code. Sometimes code gets lost, sometimes additional bits are added and there are also simple changes in a single base too. This happens during very early development but the chances of it causing a deformity are very rare. One example of a genetic deformity is sickle-cell anaemia: https://en.wikipedia.org/wiki/Sickle-cell_disease

    • Photo: Gemma Chandratillake

      Gemma Chandratillake answered on 13 Mar 2018:

      Do you mean how can a person have a physical deformity as a result of a change in their DNA?

      Changes in our DNA can happen for lots of different reasons. The processes that copy the DNA in the cell can make random mistakes sometimes, but also various chemicals can cause changes to the DNA code. This happens all the time during our lives, the DNA in our cells is constantly acquiring changes, some of which are “bad”, and this is why we can develop cancer. Things that cause DNA to change that we can control our exposure to include cigarette smoke, and UV light. But there are lots of things that cause changes to DNA that we can’t control e.g. mistakes occurring during the normal processes that happen when cells divide.

      For a person to be born with a physical deformity as a result of a change in their DNA, the change in the DNA must have occurred either in the making of the egg or sperm that came together to form the embryo, or early on in one of the cells of the embryo. Once a mistake has happened in the DNA of one cell, if it is not quickly repaired, it will be included in the DNA of all of the cells that come from that cell. Parents can’t prevent mistakes from happening in the DNA of their eggs and sperm, or early on in the development of an embryo.

    • Photo: Stéphane Berneau

      Stéphane Berneau answered on 13 Mar 2018:

      Really good question!

      During embryo development, there is a specific family of genes that are responsible for the structure and location of body part: HOMEOBOX genes.
      These genes are very well conserved between species.
      However, abnormalities can happen due to a mutation or the protein regulated by the homeobox genes expression does not respond.
      Bardet-Biedl syndrome (BBS) is a genetic condition that impacts multiple body systems. People suffering from this syndrome tend to have an extra digit on their hands and/or feet.

      Missing a body part can also be linked to lifestyle and medication. Thalidomide is a medication that was prescribed for certain types of cancers and was authorized for pregnant women. Complications were observed at birth, children were born with deformities of all four limbs. It was a big scandal.

      I hope you enjoyed my answer… Don’t forget you get another vote everyday after 3pm 🙂

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