The Kids Heart Research DNA Bank is a collection of DNA samples from individuals who have been treated for congenital heart disease at The Children's Hospital at Westmead. These samples are a critical resource to support our genetic research.
To date there is still no known cause for the majority of congenital heart diseases. Our research aims to establish links between changes in genes known to be involved in heart development and heart disease. To do this research we need to analyse DNA from large numbers of patients. Together with other research groups in Australia and around the world we are trying to identify the causes of congenital heart disease to improve our understanding of this condition and to develop better treatments.
We began collecting DNA samples from patients with 'holes in the heart' (ASDs and VSDs) in 2003. This was part of a small study looking into the genetic mechanisms involved in causing holes in the heart. In 2007, we set up the Kids Heart Research DNA Bank. We expanded our collection to include samples from patients with any type of CHD, and broadened our research aims to cover CHD in general.
A small sample of blood is collected from patients during surgery or catheterisation at The Children's Hospital at Westmead. The amount of blood varies from 2 ml (½ teaspoon) to 9 ml (2 teaspoons), depending on the age of the patient. The DNA is extracted from the white blood cells in the blood sample, processed and stored in the DNA Bank.
Anyone affected by any type of structural heart defect and having treatment at The Children's Hospital at Westmead can participate. Participants are usually recruited during their stay at the hospital. We also collect samples from parents of affected children (known as trios) as well as controls (individuals with no history, past or present, of CHD). Both groups, particularly the controls, are important for comparative research, and are essential to any study. Samples from parents and controls can be collected at The Children's Hospital at Westmead by appointment. We have also set up a contract with Symbion Laverty Pathology so participants can have their blood samples collected at their nearest Symbion Laverty Collection Centre.
All identifying information for stored samples of DNA is removed. Samples are given a unique computer-generated number which corresponds to the DNA Bank database. This database is confidential and secure and only accessible to the manager of the DNA Bank and the Genetic Counsellor. In this way samples are de-identified but are potentially re-identifiable using the numbered code. The information stored in the database, as well as the DNA, can only be used by The Children's Hospital at Westmead and their approved collaborators and colleagues working in research related to CHD. All studies and sample storage are approved by the Ethics Committee of The Children's Hospital and comply with the Privacy and Personal Information Act and the Health Information Act.
The DNA Bank is managed by a governance group of professionals:
The governance group is responsible for protecting the interests and privacy of those participating, and for ensuring that the valuable resource of the DNA Bank is put to best use from a research perspective. The group reports to the Ethics Committee of The Children's Hospital at Westmead or if advice is sought. The day-to-day issues and running of the DNA Bank are dealt with by the genetic counsellor, Dr Gillian Blue, with oversight by Professor David Winlaw.
How much blood will be required?
We will need:
2mls (½ teaspoon) of blood from children aged newborn to 2 years
5mls (1 teaspoon) from children up to 12 years old
9mls (2 teaspoons) from older children and adults.
Are there any risks to me or my child in this procedure?
There are no known risks in giving this volume of blood. In the case of your child, the blood is taken at the time of surgery when your child is anesthetised.
Can I take my DNA out of the bank?
Yes, you can request the sample to be removed from storage at any time. If you send us a written request, the sample and all records will be permanently destroyed.
Can I or my child be cloned from the DNA sample stored?
It is not possible to clone individuals from DNA alone. Furthermore, scientific and government regulation prevents human cloning.
Is there a benefit for me and my child?
Although there is no immediate personal gain from being involved, you will be helping research to identify the causes of CHD. This is likely to help develop better treatments and preventative measures.
What if you find something important in the genes?
When you agree to be involved, you can choose to be informed of discoveries relevant to you, your child or their potential offspring. If you choose to be notified, this information will be passed to your cardiologist who will discuss it with you, or arrange for this to be done in an appropriate way.
The samples stored in the DNA Bank have been used in numerous studies aimed at identifying genetic mechanisms involved in heart development and changes associated with congenital heart disease.
Whole genome sequencing studies in CHD
We are currently collaborating with Prof Sally Dunwoodie from the Victor Chang Cardiac Research Institute on a study in which we are performing whole genome sequencing (WGS) on children with CHD. WGS allows us to analyse an individual's entire genetic make-up which means we are able to discover new genes that could cause CHD. Additional consent needs to be obtained from participants in order for them to be included in this study.
Exome sequencing for novel gene discovery in CHD
As part of her PhD, Dr Gillian Blue applied exome sequencing on select families from the DNA Bank with strong histories of CHD in an attempt to identify novel causal genes. Exome sequencing rapidly analyses the entire coding sequence of an individuals' genome thereby accelerating gene discovery. The study has yielded some interesting findings which are currently being prepared for publication.
Exome sequencing in patients with congenitally corrected TGA and HLH
In this study, we are collaborating with A/Prof Paul Grossfeld a Paediatric Cardiologist and Associate Professor at the University of California, San Diego (UCSD). He is using exome sequencing to screen individuals affected by congenitally corrected TGA (ccTGA) and hypoplastic left heart (HLH) to identify new variants and genes that could be causing these heart conditions. As with the other genome/exome sequencing studies, additional consent was obtained in order for these participants to be included.
iPS cells to probe the molecular basis of congenital heart disease
We are collaborating with Prof Richard Harvey from the Victor Chang Cardiac Research Institute to investigate congenital heart disease at the molecular and cellular level using induced pluripotent stem (iPS) cell technology. The study focuses on patients with hypoplastic left heart syndrome and their families and potential participants in this study are re-consented prior to inclusion.
The CHD gene panel
As part of her PhD, Gillian Blue designed the first CHD gene panel using targeted next generation sequencing technology. This tool was used to screen 16 families in which multiple members were affected by CHD in order to identify the cause of the heart defects in the family. The CHD gene panel was able to identify the cause of CHD in 5 out of the 16 families (31%) and these findings were published in the esteemed Journal of the American College of Cardiology in December 2014 see publication list.
Wellcome Trust Genome-wide Association Study in congenital heart disease
This international collaboration used genome-wide technology to identify new genes involved in heart development. Our DNA Bank contributed 400 samples towards a total of 2000 samples analysed from the various research centres around the world. The study identified a region on chromosome 4p that was associated with an increased risk of developing atrial septal defects (ASDs). The findings of this study were published in the esteemed Journal, Nature Genetics in 2013 see publication list.
Congenital HEART and Environment/Epidemiological Database (CHeartED) is another international genome-wide association study which focussed specifically on the heart condition, Tetralogy of Fallot. Two regions on chromosomes 12q and 13q were found to be associated with Tetralogy of Fallot. The findings of this study were published in Human Molecular Genetics in 2013 see publication list.
Collaborations with Victor Chang Cardiac Research Institute
We have on-going collaborations with world-renowned developmental biologist, Professor Richard Harvey from the Victor Chang Cardiac Research Institute. Numerous genes known to be involved in heart development have been analysed using samples from the Kids Heart Research DNA Bank and several rare mutations were identified. A study on the gene GATA4 identified two novel mutations associated with cardiac septal defects and in another study, mutations identified in the gene, TBX20, were the first to link this gene to human disease and the work culminated in a high profile publication in the American Journal of Human Genetics.
GATA4 mutations as a cause for CHD
Mutations in GATA4 have been associated with both familial and sporadic forms of CHD in the past. We investigated the pathogenic role of GATA4 in CHD by screening 357 unrelated patients with various forms of CHD. We identified two novel and two known mutations in patients with septal defect and thereby added to the spectrum of mutations associated with CHD.
During research into the immune processes and B-cell development, researcher Dr Fabienne Mackay at the Garvan Institute, serendipitously discovered an association between mutations in the gene encoding CXCR7 and the development of a specific type of CHD in a mouse model. The DNA Bank contributed 300 samples to successfully confirm this association with human CHD.
The DNA Bank is a valuable resource and the only one of its kind relating to congenital heart disease (CHD) in Australia. It allows us to support both current and future research into the genetic causes of CHD and we encourage collaborations with groups both within Australia and overseas.
Access to DNA Bank samples
A letter requesting access to samples which briefly outlines the intended study and the number of samples required, and
A copy of the ethics approval letter from the premises where the research will be undertaken.
If you would like to participate in our research, or would like some more information on the DNA Bank, please contact DNA Bank Co-ordinator Dr Gillian Blue via our contact page or call her on (02) 9845 2345.