Mutation Screening Of Two Notch Signaling Pathway Related Genes And The Relationship To Simple Congenital Heart Disease

Objective: To explore the relationship between Notch2and Hey2gene mutation andsingle nucleotide polymorphism (SNP) with simple congenital heart disease (CHD)，andprovide learning theory of Notch signaling pathway occurs in congenital heart diseasebasis.Methods：50patients with congenital atrial defects，50patients with congenitalventricular septal，and100normal subjects of the same ethnical background werestudied．Five exons of Notch2gene and all five exons of Hey2gene were amplified bythe polymerase chain reaction(PCR)．The PCR products were purified and directlysequenced.Then compared with the sequence Notch2and Hey2genes in NCBIdatabase,and compared with the healthy control group, to determine whether there weremutations in the two genes.Using bioinformatic methods predicts whether Notch2gene andHey2gene point mutation affects its protein function．Results:1.No mutation was found in the exon7、exon8、exon33of the Notch2gene. Fournovel heterozygous mutations were found in the exon32of the Notch2gene: two missensemutations， with which c.C5903T （p.Ala1968Val） was found in one ASD patient,c.A5972T(p.His1976Leu）in one VSD patient, and two synonymous mutations, with whichc.C5842T（p.Leu1948Leu) in two ASD patients,c.C5925T（p.Asp1975Asp）in one ASDpatient. Ten heterozygous mutations were found in the exon34of the Notch2gene: fourmissense mutations,with which c.C6178T was found in four ASD patients, c.A6343G inone VSD patient, c.A7375G and c.C6313T in the control group; and six synonymousmutations, which c.C6561T in two ASD patients, c.A6435G、c.C6184T in one VSD patient respectively, c.C6159T in one normal subject, c.C6421T in six ASD patients、four VSDpatients、seven normal subjects, c.C6159T in one normal subject, c.T7341A in four ASDpatients、three VSD patients、seven normal subjects. Further study of cDNA6421andcDNA7341presented that there were no statistic differences of the genetype frequency andallele frequency between ventrial septal defect patients and normal controls,P＞0.05.2.Two heterozygous Notch2mutations(c.C5903T and c.C6178T) are both expected toaffect its protein function by SIFT and PolyPhen programs, while the affects to proteinfunction of another two heterozygous(c.A5972T and c.A6343G) are benign.3.No mutation was found in all five exons of the Hey2gene, while we found areported synonymous mutations（rs=112235907）.Further study presented that there wereno statistic differences of the genetype frequency and allele frequency between ventrialseptal defect patients and normal controls,P＞0.05.Conclusion:1.The mutations of Notch2gene may be related to congenital atrial septal defects inthe han nationality;2. The mutations of Hey2gene may not be associated with congenital atrial andventricular septal defects in the han nationality.