The role of Zic2 in embryonic development has been well-studied, but its role in the mature brain and/or the consequences of developmental Zic2 insufficiency in mature animals has not been fully investigated. It is possible that hypomorphic mutations that do not cause embryonic/perinatal lethality have a profound influence on higher brain functions. A pilot investigation analyzing the behavior of mice heterozygous for the hypomorphic mutation in Zic2 (Zic2kd/+) showed some abnormalities of the acoustic startle response12. However, the behaviors examined in that study were limited. A more comprehensive analysis is needed to clarify the causal relationship between the hypomorphic in Zic2 and behavioral abnormalities that might underlie neuropsychiatric disorders such as schizophrenia.