• Question: Do you think Junk DNA has something to do with pigments and albino people?

    Asked by to Lilly on 19 Mar 2014. This question was also asked by .
    • Photo: Lilian Hunt

      Lilian Hunt answered on 19 Mar 2014:

      Firstly we now know that what we initially called ‘junk DNA’ isn’t junk anymore. Some of it is pretty useful and controls when, where and how much our genes are turned on in our bodies. This is now called ‘non-coding DNA’.

      Albinism is caused by the absence or defect in an enzyme involved in producing melanin, which is the pigment that determines skin colour.

      This is all thought to be caused by mutations in our genes, not the ‘junk DNA’ in between the genes. Specifically, recessive mutations cause albinism. This is where both parents carry the mutation but also have a normal version of the gene, then their child inherits the mutated version of the gene from each parent. This means the child has 2 copies of the mutation and has a faulty gene whereas the parents each have 1 normal version and one mutated version so they don’t have the symptoms.

      We know of mutations in the human genes OCA1 and OCA2 that can cause this, as well some others.

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