Micro Deletion Syndrome Leads to Schizophrenia
Individuals with 22q11.2 micro
deletion syndrome- a rare genetic disorder will develop schizophrenia together
with one of its most common symptoms, auditory hallucinations, according to a
study done by University of Geneva Faculty of Medicine. Stephen Eliez, a
Professor in Department of Psychiatry said that patients with 22q11.2 micro
deletion syndrome, a rare neurogenetic syndrome are prone to auditory hallucinations.
More importantly 30 to 35% of them develop schizophrenia during their life time
This is the category with the highest risk of falling victim to the psychotic
About 230 people from Switzerland, France, Belgium, Luxemburg and England in the 8 to 35 age group were assesed “We discovered that the thalamic nuclei involved in auditory and vi-sual sensory processing and working memory are smaller in people with deletion syndrome than in others, explains Valentina Mancini," a researcher in UNIGE’s Department of Psychiatry. "And among people with deletion syndrome, the volume of the medial geniculate nucleus (the MGN, one of the sub-parts of the thalamus involved in the auditory pathways) and that of the other nuclei used in memory are smaller in the group with auditory hallucinations relative to the group that doesn’t experience any. The size of the MGN differs between the two groups from childhood with a divergent developmental trajectory.”
The scientists made a further observation: in the patients suffering from auditory hallucinations, they noticed a hyper-connectivity between the thalamic nuclei and cortical areas devoted to the primary processing of hearing and Wernicke’s area, which is highly significant for understanding language. This type of thalamo-cortical hyper-connection is normal during childhood, when the neural networks are being formed. The fact that it persists during adolescence and then into adulthood is the sign that the connections have never reached maturity.