Identification Of The Causative CNVs In Syndromic Congenital Heart Defects By High Resolution Array-SNP

Chapter-1Identification of the causative CNVs in Chinese syndromic congenital heart defectsObjective:The aim of the study was to identify the causative CNVs in Chinese syndromic congenital heart defects patients.Method:140syndromic congenital heart defects cases, including75male and65female, were selected for CNVs analysis. These cases were all excluded the common chromosome abnormities and genes mutations such as NKX2.5, TBX1, TBX5, and GATA4. Genomic DNA was isolated from peripheral blood leukocytes using a QIAamp DNA Blood Mini Kit (Qiagen, Valencia, CA) according to the manufacturer's instructions. The Human660w-Quad and Human Omni1-Quad Chip (illumina Inc, CA,USA) and the illumina BeadScan genotyping system (Beadstation Scanner) were employed to obtain the signal intensities of probes (SNP) following the manufacturer's instructions. The BeadStudio3.3.7software was used to analyze the genotypes and evaluate the experimental quality. The call rates of the samples are greater than99.0%. Among the21CNVs,4CNVs were validated by Real-Time PCR.Result:21pathogenic CNVs were explored in140syndromic congenital heart defects cases and the22q11.2microdeletion (9/140) was common in the causative CNVs. The4pathogenic CNVs regions were confirmed by the Real-time PCR and all of them were microdeletion variations. The results of the Real-Time PCR were equal to micro arrays'.Conclusion:1) high resolution Array-SNP was useful for the identification of the causative CNVs in syndromic congenital heart defects2)11q24-25,13q33.1-34and17p11.2were the causative CNVs regions for the syndromic congenital heart defects Objective:The aim of the study was to explore the relationship between the two candidate causative genes and non-syndromic congenital heart defects.Method:45nonsyndromic congenital septum defect cases, including congenital atrium septum defect in15cases, congenital ventricle septum defect in15cases and complete atrioventricular septum defects in15cases were selected for the EFNB2mutation sequencing. We also chose38congenital double outlet of right ventricle (DORV) for the ZFPM/FOG2mutation sequencing. Before the mutation sequencing, we had excluded the common genes mutations such as NKX2.5, TbXl, TbX5and GATA4. Genomic DNA was isolated from peripheral blood leukocytes using a QIAamp DNA Blood Mini Kit (Qiagen, Valencia, CA) according to the manufacturer's instructions. Primers were designed for the Polymerase Chain Reaction (PCR). The PCR products were used for the mutation sequencing by ABI3100Genetic Analyzer according to its protocol. The test would be repeated for3times once the causative gene mutations were discovered.Result:5ZFPM/FOG2mutations were found in38DORV cases. Three novel mutations (p.V339I.p.K737E, and p.A611T) were reported for the first time. The other two mutations (p.M703L and p.Q889E) were reported in patients with congenital diaphragmatic hernia but not in patients with CHD. Besides that, one EFNB2mutations were found in45congenital septum defects cases. This synonymous mutation was found in a congenital ventricular septum defects caseConclusion:1) variants of the ZFPM2/FOG2gene might be a common cause of DORV, but the ZFPM2/FOG2mutations could not used in distinguishing the types of the DORV.2) We suggest that EFNB2should not be the candidate causative gene for congenital heart defects and there would be some other genes which are responsible for the CHD.