PURA syndrome is a rare genetic condition.
Our individual characteristics or traits (e.g. eye colour) are determined by our genes. Our genes encode instructions to make different types of proteins and these are important in how our body works in daily life.
Genes are packaged into chromosomes. We have 23 pairs of chromosomes, so 46 chromosomes in total. In each pair, there is one chromosome inherited from the mother and one inherited from the father and therefore we should have two copies of each gene. The chromosome pairs are labelled 1-22 (autosomes) and the sex chromosomes (XX if girl, XY if boy). Each chromosome has a p arm and a q arm. The p arm is the shorter arm and the q arm is the longer arm.
In the case of PURA syndrome there is a mutation or deletion in all, or part of, the PURA gene. The PURA gene is on the 5th chromosome on the q arm. The PURA gene encodes an important protein called Pur-alpha. This is present in many cells in your body and is important in the production and replication of DNA. Pur-alpha protein is especially important in brain development. We see the symptoms of PURA as the Pur-alpha protein doesn’t work as well as in someone who has an unaffected PURA gene.
To have PURA syndrome, only one of the PURA genes needs to be altered. This means that it is autosomal dominant. However, in the majority of cases no one else in the family is affected and the mutation is new. This new ‘out of the blue’ mutation is called a de-novo mutation. If parents do not have the same PURA change as their child it is considered a de-novo change and therefore the risk to other children is low. However, to best understand risk for future pregnancies, it is worth consulting a geneticist.
Most of the initial problems seen with our PURA patients are not very specific and can be seen in other conditions. It may be that your child had some genetic testing a while ago and you have only recently been told they have PURA syndrome. This is because the PURA gene and PURA syndrome has only recently been identified and the test may not have looked at the PURA gene.