Characterizing the role of CECR1 in cat eye syndrome by using mouse models

Abstract

CECR1 (cat eye syndrome chromosome region, candidate 1) is located on chromosome 22q11.2. Duplication of this region results in the human disorder cat eye syndrome (CES), which includes a variety of heart defects. CECR1 is suggested to be dosage sensitive, based on a predicted role in controlling extracellular adenosine level during development, and thus may be responsible for some of the CES features, including heart abnormalities. Animal models were established to study the effect of overexpressing CECR1 in hearts. Abnormal phenotypes in hearts were not detected in zebrafish embryos overexpressing zebrafish cecr1. Thinner right ventricular walls and atrioventricular (AV) valve disorganization were observed in embryos of the transgenic mouse line FVB/N-Tg(MHC-hCECR1), which expressed human CECR1 specifically in cardiac muscle. The observed phenotypes were not typical of patients with CES; however, disrupted adenosine level resulting from increased adenosine deaminase activity might be responsible for the phenotypes.