By Devika Sunand
The Cardiff university ECHO research team who aims to understand the life course of individuals with 22q112.2 Deletion syndrome (22q11.2DS) has found a link between the sleep patterns and mental health issues. 22q12.2 Deletion syndrome also known as DiGeorge syndrome, is caused by the deletion of a small segment of a chromosome. Almost 90% of cases occur due to new mutation of a chromosome during the early stages of development while 10% is inherited from the parents. Even though the symptoms vary, some of the common ones include congenital heart problems, specific facial features, frequent infections, developmental delay, learning problems, and cleft palate. It is estimated that people affected by deletion syndrome can range between 1 in 2000 to 1 in 4000 live births but the actual figure can be higher than expected since not all of the individuals may be diagnosed.
The study was conducted on children and adolescents in the age group of 17 and below with the deletion syndrome. Researchers found that 60% of the group experienced insomnia or restless sleep and a higher proportion of these had conditions like ADHD, anxiety disorders and conduct disorder. Also, sleep problems are likely to lead to movement problems which can make them more clumsy and reduce their planning ability. For the study, the children diagnosed with the deletion syndrome participated along with their siblings. This was to understand the difference in sleep patterns as a result of the mutation. The mental health and intelligence of children with the syndrome were investigated and compared to their siblings who did not have the syndrome. Studies have shown that 54% of children met the criteria for a mental health condition, compared to 10% of their siblings. The average IQ of children with the deletion syndrome was 77, which was considerably less than their siblings who had an average IQ of 109. It was also found that children with the syndrome are likely to perform worse on tests of attention, planning and reaction time. However, no relationship was found between the presence of a mental health condition and the child’s intelligence.
A separate study to understand whether ADHD is similar or different in children with and without the syndrome showed that children with deletion syndrome were less attentive and more anxious. They were less hyperactive and had less conduct issues compared to children who did not have the syndrome. The percentage of children receiving treatment for ADHD was as low as 2%. In conclusion, the clinical representation of ADHD in children with the deletion syndrome were found to be different to typical ADHD, potentially leading to an under-recognition of ADHD in this patient group by the clinicians.
Awareness of deletion syndromes have become extremely important, due to the confusion is causes parents because of its varied symptoms. Studies showed that while 78% of parents were aware of the deletion syndrome, they were twice as likely to have found out about this from the internet than a clinician.