Why do we study genetics?
Genetics is the study of family traits, or how traits (e.g. eye colour) are passed on from parents to children. We hope that in the not-too-distant future, doctors will be able to use genetic information to help diagnose, treat, prevent and cure many diseases. Our genes contain the instructions our body uses to build and regulate proteins. When these instructions have minor changes or faults it means our bodies can’t always build everything correctly, or at the right time. By understanding some of these genetic changes, we hope that it will help us understand why the body doesn’t always function perfectly, and how we might be able to correct things when they go wrong. We hope that this might one day lead to more effective medicines and treatments, and perhaps even cures for conditions such as JIA.
What is a biobank?
A biobank is a large collection of personal health and medical information (data), tissue samples and other biospecimens that are collected for research purposes. The samples and associated data are very carefully collected. Patient names are removed from the biospecimens before storage in freezers that get as cold as -150oC. This helps preserve the samples over a long time, meaning many research questions can be answered now, and in the future. One big advantage of a biobank is that a large number of samples can be collected over time and in the same way. This means that researchers have access to enough data to identify links with disease that are often not able to be seen when only looking at a small number of samples at once.
What are we currently researching?
Towards a Diagnostic Test for JIA
We believe that genetic information from across the whole human genome can be used to develop a test to predict JIA. This could be used when children first present to clinics (like your GP or local paediatrician) with musculoskeletal (joint, muscle, ligament, etc.) symptoms. This project brings together researchers from Australia, the UK and the US to better use existing genetic data to develop a JIA risk score. This is a score that indicates how likely a person is to develop JIA based on their genetics. We then plan to take this new risk score and test how effective it is in paediatric rheumatology clinics across Australia. This new, very exciting project is currently funded by the National Health and Medical Research Council (NHMRC)
Sex-specific Risk for JIA
Another of our ongoing research projects uses different methods to determine how the risk of developing JIA might differ between the sexes. Many more girls get JIA than boys. We have looked at 68 genetic changes known to be associated with developing JIA overall. We have shown for the first time that several of these genetic changes increase risk of developing JIA differently between boys and girls. This work suggests the genetic causes of JIA differs between the sexes. To take this further we are now investigating whether genetic changes on the Y chromosome, which only boys have, might contribute to risk of developing JIA in males.
The role of Vitamin D and Sunshine in JIA
We are also very interested in investigating the role of the environment in JIA risk. We know that sunlight is an important way our bodies get vitamin D. Researchers have previously shown that vitamin D is important in immune health. We are therefore looking to see whether reduced time in the sun across a child’s life (including in the womb) is associated with risk of developing JIA.
Are DNA methylation patterns different in children with JIA?
DNA methylation is an ‘epigenetic’ chemical modification to DNA that sits above the DNA sequence and helps to regulate the activity of genes. DNA methylation across the genome can change across a person’s life, often in response to changes in the environment. We are looking to see whether children with JIA have a different DNA methylation pattern across the genome compared with children who don’t have JIA. If they do, this might provide new information about the genes that are incorrectly regulated in JIA, and importantly, how these genes are interacting with the environment.
Which genes are acting differently in children with JIA?
Genes are transcribed to an intermediate molecule called messenger RNA (mRNA), and then translated to proteins. The amount of mRNA that is produced by a gene is regulated by the DNA sequence, and by epigenetics (such as DNA methylation, see above). By measuring and comparing the amount of mRNA produced by (almost) all the genes in the genome in children with and without JIA we can identify at which genes something has gone wrong. This will increase our knowledge of the causes of JIA, and provide new opportunities for developing treatments to put things right.