A missing piece of DNA may hold clues about how schizophrenia and other psychiatric disorders develop. People who are missing a small section of chromosome 22—a region called 22q11.2—lose one copy of as many as 45 different genes. This is frequently referred to as the “22q11.2 deletion syndrome.” The syndrome has been linked to many debilitating conditions, including heart abnormalities, intellectual disability and an increased risk for developing various mental illnesses.

These deletions are rare occurrences, making it difficult for researchers to get a complete picture of their consequences. A new study published June 1st in The American Journal of Psychiatry tries to remedy this by pooling and examining global data from 1,402 people with 22q11.2 deletions, aged 6 to 68 years. Conducted by the International Consortium on Brain and Behavior in 22q11.2 Deletion Syndrome, the researchers focused their examination on the occurrence of psychiatric disorders.

The study reports the following links between 22q11.2 deletion syndrome and mental illness:

•    Schizophrenia spectrum disorders occurred in more than 40 percent of adults with 22q11.2 deletions, higher than previously thought

•    Anxiety disorders featured prominently across the lifespan, as it was diagnosed in one-quarter to one-third of each age group, including children

•    Attention deficit-hyperactivity disorder (ADHD) predominated in childhood, where it was diagnosed in 37 percent of 6 to 12-year-olds, but was less common in older subjects

The findings suggest that more study of the deletion syndrome can provide further clues about the genetics underlying these illnesses. The research team also argues that awareness and early treatment of these conditions should be part of the clinical management of people with 22q11.2 deletions.

NARSAD Grantees that participated in this large study include: 2013 NARSAD Young Investigator Grantee Marco Armando, M.D., Ph.D., Bambino Gesu' Children's Hospital; 2012 NARSAD Young Investigator Grantee Martin Debbané, Ph.D., University of Geneva; 2010 NARSAD Young Investigator Grantees Jacob A.S. Vorstman, M.D., University Medical Center Utrecht and Vandana Shashi, M.D., MBBS, Wake Forest University; 2008 NARSAD Young Investigator Grantee Opal Ousley, Ph.D., Emory University School of Medicine; 2006 NARSAD Young Investigator Grantee Doron Gothelf, M.D., Tel Aviv University; 2005 NARSAD Independent Investigator Grantee Wendy R. Kates, Ph.D., Johns Hopkins University; 2005 NARSAD Young Investigator Grantee Carrie E. Bearden, Ph.D., University of California, Los Angeles; 2004 NARSAD Young Investigator Grantee Therese van Amelsvoort, M.D., MRCPsych, MSc, Ph.D., University of Amsterdam; 2002 NARSAD Young Investigator Grantee Stephan Eliez, M.D., Ph.D., University of Geneva; 2002 NARSAD Distinguished Investigator Grantee Anne Bassett, M.D., FRCPC, University of Toronto; 2000 NARSAD Independent Investigator Grantee Michael Owen, M.D., Ph.D., Cardiff University; 1999 NARSAD Distinguished Investigator Grantee Raquel E. Gur, M.D., Ph.D., University of Pennsylvania; and 1997 NARSAD Young Investigator Grantee Eva Chow, M.D., University of Toronto.

Read the abstract of this research paper.

Read more about this research on the Schizophrenia Research Forum.