We have previously shown that Tbx1 heterozygous mice have reduced prepulse inhibition, a behavioral abnormality that is associated with 22q11.2DS and nonsyndromic schizophrenia.
Velocardiofacial (VCFS; 22q11.2 deletion) syndrome is a genetic disorder that results from a hemizygous deletion of the q11.2 region on chromosome 22, and is associated with greatly increased risk for psychiatric disorders, including autism spectrum disorder (ASD) and schizophrenia.
A study has also shown that phenotypic features of 22q11 deletion syndrome (22q11DS) were segregated with an inactivating mutation of TBX1 in one family, suggesting that the TBX1 gene plays a role in the pathogenesis of some psychiatric disorders.
Based on these results we conclude that TBX1 variation does not make a strong contribution to the genetic etiology of nonsyndromic forms of psychiatric disorders commonly seen in patients with 22q11DS.
A likely role for Tbx1 haploinsufficiency in psychiatric disease is further suggested by the identification of a family in which the phenotypic features of 22q11DS, including psychiatric disorders, segregate with an inactivating mutation of TBX1.
The identification of candidate genes for heart anomalies, mental illness, and other clinical phenotypes has been reported in the past year with a focus on TBX1 for cardiac and craniofacial phenotypes and COMT and PRODH for psychiatric disorders.
Although Tbx1 has been shown to be responsible for many physical defects associated with 22q11.2 haploinsufficiency, Tbx1 heterozygous mice did not display these behavioral abnormalities.