الفهرس 
Anatomical ConsiderationsOnly 14 pages are availabe for public view
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Abstract
Congenital heart disease is a general term used to describe abnormalities of the heart or great vessels that are present from birth.Most such disorders develop from faulty embryogenesis during 3rd -8th gestational weeks, when major cardiovascular structures undergo development, although some severe disorders may be compatible with intra uterine survival, most are associated with live births. Some may produce manifestations soon, thereafter, frequently accompanying the change from fetal to post natal circulatory patterns, others however do not necessary become evident until adulthood (e.g. aortic coarctation or ASD.The incidence of congenital heart disease is the most common type of heart disease among children, although figures vary, a generally accepted incidence is 6 to 8 per 1000 live born full term births, the incidence is higher in premature and still born.The cause of congenital heart disease is not known in most of patients, multifactorial: genetic ,environmental inputs and genetic environmental interactions are suspected Congenital heart defects may occur 1- as a part of a genetic syndrome or 2- as an isolated defect Genetic syndromes are either due to chromosomal abnormalities (eg trisomy 13, 18 and 21) or single gene defects (eg Allagille syndrome Noonan syndrome and Holt-Oram syndrome) Isolated cardiac defects are due to mutations in NKX2.5, GATA4 and NOTCH1 The varied structural anomalies in the heart with congenital defects fall primarily into two major categories: cyanotic and non-cyanotic The MTHFR gene The human MTHFR gene is located on chromosome I p36.3 Common mutations in the MTHFR gene Mutation at nucleotide 677:- It is a point mutation located in exon 4 within the catalytic domain at the folate binding site (677C→ T), converting a cytosine (C) into athymine (T) this mutation results in an amino acid substitution (alanine to valine Among healthy subjects, the 677TT genotype is associated with a significantly higher total homocysteine plasma level than in heterozygotes or individuals with wild-type C alleles Patients and Method 1- Group I (Congenital heart disease patients) their age was from 1 month to 72 months and their gender was 9 males and 11 females 2- Group II (Control group) their age was from 2 months to 66 months and their gender was 10 males and 10 females All were selected from pediatric cardiology clinic and PICU of Menufiya university and were subjected to 1- Complete history taking ( personal, present, past, obstetric and family history). 2- Thorough physical examination ( general and cardiac 3- Investigations (chest X ray, ECG, echocardiography 4- Molecular genetic study for determination MTHFR genotype in Genetics Unit Pediatrics department Menufiya University Hospital 5- Genetic counseling The Results Normal gene (CC) was found in 10 (50%) and Polymorphism(CT/TT) was found in 10 patients (50% CT polymorophism was found in 5% and TT polymorphism in 45% The frequency of wild type allele (C) in the patients group was 52.5% and in the control group was 60% The frequency of deficient type allele (T) in the patients group was 47.54% and in the control group was 40% The total frequency of wild type allele (C) in both patients and control was 56.25%. The total frequency of deficient type allele (T) in both patients and control was 43.75% The frequency of wild type allele (C) in the males was 52.8% and in the females was 59% The frequency of deficient type allele (T) in the males was 42.7% and in the females was 41% br There is no statistical difference of alleles frequency distribution between males and females There is non significant difference between normal gene and gene polymorphism regarding demographic data ( 0.05). Conclusion Regarding the genetic study we found no association between MTHFR gene polymorphism and congenital heart defects.