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A hidden condition

17 March 2015

Swirl of colourful chromosomal diagram

Children and adults living with a poorly understood chromosomal condition are 25 times more likely to develop schizophrenia than the general population, according to a report by Cardiff researchers.

Affecting an estimated 35,000 people in the UK, 22q11.2 Deletion Syndrome (22q11.2DS) is caused by the deletion of a small amount of DNA from a person's chromosome 22. Babies who inherit the condition are often born with serious health problems as well as issues affecting normal development.

A team of researchers from the University's ECHO research team (Experiences of people with copy number variation) were this week invited to Westminster for the launch of an All-Party Parliamentary Group (APPG) to increase awareness of 22q11.2DS and the support received by parents affected by the condition.

Julie Wootton, chair of trustees for the 22q11.2DS support group, Max Appeal, said: "We are delighted to be launching the APPG at this awareness event and are incredibly grateful to Jack Lopresti MP and the MP's putting their weight behind it.  We hope that this will help to raise both awareness and understanding of the needs of these families, their children and adults living with the condition."

Study leader, Professor Marianne van den Bree, from Cardiff's Institute of Psychological Medicine and Clinical Neurosciences, said: "Having interviewed parents across the UK about their children with 22q11.2DS, we have found very high rates of intellectual, developmental and a range of mental health problems, the extent of which is largely unknown by the medical community or policymakers."

Researchers found that the main issues confronting children born with 22q11.2DS include: intellectual disability (~30% of cases); Attention Deficit Hyperactivity Disorder (ADHD, ~40%); autism (~26%); dyspraxia (~81%); and sleep disturbances (~22%). Furthermore, in adulthood, patients have an increased risk of developing schizophrenia (25 times more likely to be affected than people in the general population).

Cardiff PhD researcher, Samuel Chawner, said: "Our findings indicate that these risks depend to some degree on the developmental stage of the child. For example, the rate of ADHD declines somewhat when children reach adolescence, while risk of low mood increases slightly."

Parents frequently report that they do not get the support they need for their child, Prof van den Bree added. "Society, including medical and other professionals, has generally never heard of the syndrome, and this creates a barrier for accessing much needed services. Children and their parents frequently have to cope with lack of understanding in other settings, such as the school."

According the researchers, children tend to be referred for genetic screening because of physical or developmental problems. The ECHO study, however, has found that there is great variation between services in how parents are told about their child's diagnosis. Parents are often not told by clinicians about the risk their child carries of developing mental health problems. As a consequence, they tend to learn about these complicated problems when browsing the internet, rather than with the guidance of a clinical expert.

In addition, there is currently insufficient scientific information about the likely course of the condition from childhood to adolescence and into adulthood. Parents therefore do not know what lies around the corner. These important issues need to be addressed by studying patients over time.

Dorne Mitchell is mother to Ivy, aged 2, who lives with 22q11.2DS. She said: "As we reached the last two weeks of our pregnancy we received the bombshell that our little girl appeared to have abnormalities. A test confirmed that Ivy had 22Q11 – a condition we'd never heard of – along with that came the devastating news that she had a rare and complex cardiac problem which would require open heart surgery throughout her life."

The ongoing ECHO study is currently tracking 130 families affected by 22q11.2DS throughout the course of their lives – one of few studies to do so. By presenting their findings to politicians, clinical experts and patient support groups the Cardiff team hopes to increase awareness of the condition, gain funding for further research and discuss ways of improving support for the condition.

The researchers believe that understanding why individuals with 22q11.2DS are at increased risk of developing mental health problems can ultimately also provide important insights into these conditions in the general population.

The research was funded by Waterloo Foundation, the National Institute of Health (NIH), Wellcome Trust and The Baily Thomas Charitable Fund.

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