[Mutation analysis of Cited2 in patients with congenital heart disease]

To explore mutation of Cited2 gene coding strand in Chinese patients with congenital heart disease (CHD).

DNA was extracted from the blood samples of 120 nonhomologous and various CHD patients and 100 healthy children. The sequence of coding regions of Cited2 was amplified by PCR and compared to those in the GeneBank after sequencing to identify the mutations. The family of the samples who have Cited2 mutations were investigated as well. Clustal W software was applied for conservative analysis of the altered amino acids.

Three new mutations of Cited2 coding strand were found in 4 CHD patients. Two point mutations were first identified respectively in two patients, one patient with mirror image dextrocardia and tetralogy of Fallot (c.550 G > A), another with aortic stenosis (c.574 A > G). Apart from this, the same deletion (c.573-578del6) was first detected in another two patients, one with ventricular septal defect and atrial septal defect, the other with aortic stenosis and pulmonary stenosis. All the mutations resulted in the protein changes (p.Gly184Ser; p.Ser192Gly; p.Ser192fs). None of these changes were detected in the control group.

This study showed that there are 3 brand-new gene mutations as demonstrated by sequencing of Cited2 gene in Chinese CHD patients with a broad phenotype spectrum. Serine-glycine rich junction (SGJ) is considered as the mutation hot spot. Cited2 mutations may be one of the causes of the development of CHD in human.