UC Davis researchers have found that for children with the genetic disorder known as chromosome 22q11.2 deletion syndrome anxiety -- but not intelligence -- is linked to poorer adaptive behaviors, such as self-care and communication skills, that affect daily life. The developmental syndrome, which is associated with a constellation of physical, cognitive and psychiatric problems, usually is apparent at birth or early childhood, and leads to lifelong challenges.
The study findings suggest that helping children cope with fear-based symptoms may be the best strategy for increasing independence and protecting against psychiatric problems later in life. The article, titled, "An examination of the relationship of anxiety and intelligence to adaptive functioning in children with chromosome 22q11.2 deletion syndrome," is published online today in the Journal of Developmental and Behavioral Pediatrics. It will appear in the December 2012 print issue of the journal.
"Our study confirmed our impressions from seeing patients with 22q deletion syndrome that those with more severe anxiety symptoms tend to be most impaired in their everyday functioning," said Kathleen Angkustsiri, lead study author and assistant professor of developmental and behavioral pediatrics with the UC Davis MIND Institute. "It highlights the critical importance of recognizing and treating anxiety in these very vulnerable children."
The disorder also is known as velocardiofacial syndrome, referring to some of the common physical anomalies associated with the disorder, as well as DiGeorge syndrome, after one of the first physicians to describe it. The currently preferred name of chromosome 22q11.2 deletion syndrome identifies the location on the twenty-second chromosome where a small piece of DNA is missing. It is inherited in an autosomal dominant fashion, meaning that the child of a parent with the syndrome has a 50 percent chance of developing the syndrome; however, in 90 to 95 percent of cases, no family history of the syndrome is known, and the mutation arises for the first time in the affected person. The syndrome is estimated to affect about 1 in 2,000-4,000 people, making it the second most common condition after Down syndrome, another genetically based developmental disorder.
Manifestations of the syndrome vary among affected individuals. It may be diagnosed soon after birth because of symptoms related to heart defects as well as anomalies of the mouth, palate and throat, affecting feeding, speech and facial structure. Children with 22q11.2 deletion syndrome have a high prevalence of mental-health disorders such as anxiety and attention deficit hyperactivity disorder (ADHD), and IQs usually are in the borderline-to-low range. In early adulthood, about 30 percent may develop a psychiatric disorder such as schizophrenia.
The study evaluated 78 children with the syndrome, ages seven to 15 years, with a battery of standardized tests related to behavior, anxiety, adaptive functioning and intelligence. Thirty-six typically developing children with no known genetic syndromes were also evaluated for comparison. Assessment involved neuropsychological testing and developmental-behavioral pediatric evaluation of the children as well as parent questionnaires about their child's symptoms.
Mean anxiety scores were found to be significantly higher in children with 22q11.2 deletion syndrome than in typically developing children. Fifty-eight percent of children with the syndrome were found to have at least one elevated anxiety score, although only 19 percent had previously been diagnosed with an anxiety disorder.
In addition, higher anxiety scores correlated with lower adaptive function among children with the syndrome. Adaptive functioning is a measure of age-appropriate everyday living skills surrounding self-care, home and school living, communication and other factors. Specific anxiety subscales that were associated with poorer adaptive behavior included panic-agoraphobia (anxiety associated with unfamiliar environments), physical injury and obsessive-compulsive disorder.