Risk factors for congenital heart diseases in Alexandria, Egypt

Identifying the Factors Affecting the Incidence of Congenital Heart Disease Using Support Vector Machine and Particle Swarm Optimization

Background

Congenital malformations are defined as "any defect in the structure of a person that exists from birth". Among them, congenital heart malformations have the highest prevalence in the world. This study focuses on the development of a predictive model for congenital heart disease in Isfahan using support vector machine (SVM) and particle swarm intelligence.

Materials and Methods

It consists of four parts: data collection, preprocessing, identify target features, and technique. The proposed technique is a combination of the SVM method and particle swarm optimization (PSO).

Results

The data set includes 1389 patients and 399 features. The best performance in terms of accuracy, with 81.57%, is related to the PSO-SVM technique and the worst performance, with 78.62%, is related to the random forest technique. Congenital extra cardiac anomalies are considered as the most important factor with averages of 0.655.

Conclusion

Congenital extra cardiac anomalies are considered as the most important factor. Detecting more important feature affecting congenital heart disease allows physicians to treat the variable risk factors associated with congenital heart disease progression. The use of a machine learning approach provides the ability to predict the presence of congenital heart disease with high accuracy and sensitivity.

Association Between Maternal Factors and Risk of Congenital Heart Disease in Offspring: A Systematic Review and Meta-Analysis

INTRODUCTION

This study aimed to summarize the evidence describing the relationship between maternal factors during gestation and risk of congenital heart disease (CHD) in offspring.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched for potentially relevant reports from inception to May 2021. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) calculated by the random-effects model were used to evaluate the association between maternal factors and CHD risk.

RESULTS

There was a significant association between CHD risk and obesity in pregnancy (OR 1.29, 95% CI 1.22-1.37; P < 0.001), smoking in pregnancy (OR 1.16, 95% CI 1.07-1.25; P < 0.001), maternal diabetes (OR 2.65, 95% CI 2.20-3.19; P < 0.001), and exposure of pregnant women to organic solvents (OR 1.82, 95% CI 1.23-2.70; P = 0.003). No correlations were revealed between CHD susceptibility and advanced maternal age (OR 1.04, 95% CI 0.96-1.12; P = 0.328), underweight (OR 1.02, 95% CI 0.96-1.08; P = 0.519), alcohol intake in pregnancy (OR 1.08, 95% CI 0.95-1.22; P = 0.251), coffee intake (OR 1.18, 95% CI 0.97-1.44; P = 0.105), and exposure to irradiation (OR 1.80, 95% CI 0.85-3.80; P = 0.125).

DISCUSSION

Maternal factors including maternal obesity, smoking in pregnancy, maternal diabetes and exposure to organic solvents might predispose the offspring to CHD risk.

Mutation spectrum of congenital heart disease in a consanguineous Turkish population

BACKGROUNDS

While many studies agree that consanguinity increases the rate of congenital heart disease (CHD), few genome analyses have been conducted with consanguineous CHD cohorts.

METHODS

We recruited 73 CHD probands from consanguineous families in Turkey and used whole-exome sequencing (WES) to identify genetic lesions in these patients.

RESULTS

On average, each patient had 6.95 rare damaging homozygous variants, 0.68 of which are loss-of-function (LoF) variants. Seven patients (9.6%) carried damaging homozygous variants in five causal CHD genes. Six of those patients exhibited laterality defects (six HTX and one D-TGA). Three additional patients (4.1%) harbored other types of CHD-associated genomic alterations, which overall explained 13.7% (10/73) of the cohort. The contribution from recessive variants in our cohort is higher than 1.8% reported from a cohort of 2871 CHD subjects where 5.6% of subjects met the criteria for consanguinity.

CONCLUSIONS

Our WES screen of a Turkish consanguineous population with structural CHD revealed its unique genetic architecture. Six of seven damaging homozygous variants in CHD causal genes occur in the setting of laterality defects implies a strong contribution from consanguinity to these defects specifically. Our study thus provided valuable information about the genetic landscape of CHD in consanguineous families in Turkey.

Familial partial atrioventricular septal defect in four related kindreds: case series and review of the literature

Background

Atrioventricular septal defects are common congenital heart defects and comprise a spectrum of anomalies, these defects were described in few pedigrees suggesting a familial pattern of inheritance, and they are more common in patients with chromosomal abnormalities. The familial occurrence of this particular type of congenital heart disease is uncommon and few cases have been identified as partial atrioventricular septal defect in adults apart from other chromosomal abnormalities.

Case presentation

We report four cases of adult females who were diagnosed with partial atrioventricular septal defect in four related families, our patients do not have the morphology of Down syndrome.

Conclusions

Further researches on genotyping such patients might contribute to our knowledge regarding this particular cardiac malformation.

Parental risk factors associated with congenital heart disease in a Thai population: multivariable analysis

Background

Congenital heart diseases (CHDs) are the most common types of birth defects and contribute to a large proportion of infant morbidities and mortalities worldwide. These defects may require multiple surgical interventions impacting the infant's quality of life.

Objectives

To identify risk factors associated with CHD in a population of Thai children.

Methods

We conducted a case-control study of patients attending the Pediatric Clinic, Naresuan University Hospital, Thailand. We included data from pediatric patients diagnosed with CHDs as cases, and patients without cardiovascular abnormalities as controls. Risk data were collected from July 2019 to April 2020 using face-to-face interviews. Multiple logistic regression was used to analyze parental factors associated with CHDs.

Results

We included 249 cases classified into 2 groups according to severity and 304 patients as controls. For those less-severely affected (155 patients, 62.2%), ventricular septal defect (27.7%) was the most prevalent, whereas for those with severe CHDs, tetralogy of Fallot was the most prevalent (14.0%). There was no difference in sex distribution or maternal obstetric history between the groups. In multivariable analysis, a family history of CHDs (adjusted odds ratio [AOR] 4.67, 95% confidence interval (CI) 1.61-13.57, P = 0.005) and maternal exposure to second-hand cigarette smoke (AOR 1.58, 95% CI 1.03-2.42, P = 0.002) were identified as significant risk factors for CHDs.

Conclusion

A family history of CHDs and maternal exposure to second-hand cigarette smoke are associated with having offspring with CHDs in the population studied. These findings help us to encourage affected parents to obtain a fetal echocardiogram.

Association between advanced paternal age and congenital heart defects: a systematic review and meta-analysis

STUDY QUESTION

Is there an association between advanced paternal age and congenital heart defects (CHD)?

SUMMARY ANSWER

Advanced paternal age is associated with a 16% increase in the overall odds of CHD.

WHAT IS KNOWN ALREADY

CHD are the most common congenital malformations. Several risk factors for CHD have been identified in the literature, but the association between advanced paternal age and CHD remains unclear.

STUDY DESIGN, SIZE, DURATION

We conducted a systematic literature search on MEDLINE and EMBASE (1960-2019) to identify studies assessing the association between advanced paternal age (≥35 years) and the risk of CHD, unrestrictive of language or sample size. We used a combination of Medical Subject Headings (MeSH) terms and free text words such as 'paternal age', 'paternal factors', 'father's age', 'parental age', 'heart', 'cardiac', 'cardiovascular', 'abnormalities, congenital', 'birth defects', 'congenital malformations' and 'congenital abnormalities'.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included observational studies aiming at assessing the association between paternal age and CHD. The included population could be live births, fetal deaths and terminations of pregnancy for fetal anomaly. To be included, studies had to provide either odds ratios (OR) with their 95% confidence interval (CI) or sufficient information to recalculate ORs with 95% CIs per paternal age category. We excluded studies if they had no comparative group and if they were reviews or case reports. Two independent reviewers selected the studies, extracted the data and assessed risk of bias using a modified Newcastle-Ottawa Scale. We used random-effects meta-analysis to produce summary estimates of crude OR. Associations were also tested in subgroups.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 191 studies identified, we included nine studies in the meta-analysis (9 917 011 participants, including 34 447 CHD), including four population-based studies. Five studies were judged at low risk of bias. Only one population-based study specifically investigated isolated CHD. The risk of CHD was higher with advanced paternal age (summary OR 1.16, 95% CI, 1.07-1.25). Effect sizes were stable in population-based studies and in those with low risk of bias.

LIMITATIONS AND REASONS FOR CAUTION

The available evidence did not allow to assess (i) the risk of isolated CHD in population-based studies, (ii) the association between paternal age and the risk for specific CHD and (iii) the association between paternal age and CHD after adjustment for other risk factors, such as maternal age.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that advanced paternal age may be a risk factor for CHD. However, because the association is modest in magnitude, its usefulness as a criterion for targeted screening for CHD seems limited.

STUDY FUNDING/COMPETING INTEREST(S)

None.

PROSPERO REGISTRATION NUMBER

CRD42019135061.

Risk factors for transposition of the great arteries in Saudi population

Objectives:

To assess potential risk factors and their effect on the development of transposition of the great arteries (TGA).

Methods:

A retrospective case-control study of all patients diagnosed with TGA between 1999 to 2016 at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Age and gender-matched controls were selected. Risk factors, including consanguinity, gestational diabetes, family history of congenital heart disease, parental age, and maternal parity, were collected. Regression modeling was used to analyze the effects of risk factors on the development of TGA.

Results:

A total of 206 patients with transposition of the great arteries were enrolled in the study. Transposition of the great arteries cases were divided into simple and complex TGA. Selected healthy controls were 446. In the studied cases, consanguinity was found in 95 (46%) of cases, gestational diabetes was diagnosed in 36 (17.5%) mothers, and 35 (17%) had a confirmed family history of congenital heart disease. When risk factors of the cases were compared to the controls, consanguinity, gestational diabetes, maternal age, and parity were found to significantly increase the incidence of TGA.

Conclusion:

Our study revealed significant risk factors for the development of transposition of great arteries including first degree consanguineous marriages, gestational diabetes, family history of congenital cardiac anomalies, and increasing maternal age and parity. These factors increased the risk by at least 2 folds.

Pattern of congenital heart disease among Egyptian children: a 3-year retrospective study

BACKGROUND

Congenital heart disease (CHD) is a multifactorial birth defect which has variable demographic characteristics among children in different geographical areas. This study aimed to detect the distribution of demographic data, perinatal risk factors, types, age, and mode of presentation of CHD among Egyptian children.

RESULTS

The medical records of 1005 patients were included. They were 545 males (54%) and 462 females (46%) with a ratio of 1.2:1. Acyanotic CHD was encountered in 79.2%. Isolated ventricular septal defect and tetralogy of Fallot were the most common acyanotic and cyanotic lesions, respectively. The majority was diagnosed within the first year of life (86.7%) and was born to young mothers (91.3%). The accidental discovery of a murmur was the most frequent presentation (35%). Heart failure was detected in 44%, audible murmurs in 74.4%, maternal illnesses in 54%, consanguinity in 44.6%, prematurity in 19.3%, assisted reproduction in 11.7%, family history of CHD in 9.2%, abortions in 7.1%, and extracardiac anomalies in 3.6% of the studied population. Down syndrome (DS) was the most commonly occurring chromosomal anomaly, and the atrioventricular septal defect was the most characteristic cardiac lesion found among them.

CONCLUSIONS

There is no sex predilection among Egyptian children with CHD. Most of the cases are diagnosed in early infancy. Accidental discovery of a murmur is the most common mode of presentation. A variety of predisposing risk factors are abundant in the Egyptian population. DS is the most common chromosomal anomaly linked to CHD. Establishment of a national medical birth registry containing all information about all births in Egypt is needed for adequate surveillance and monitoring of perinatal health problems and congenital birth defects so that preventive measures can be early implemented. Proper and detailed data collection should be fulfilled in the medical records of every single patient.

Effect of paternal age on offspring birth defects: a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis was aimed at determining whether paternal age is a risk factor for offspring birth defects.

RESULTS

A total of 38 and 11 studies were included in the systematic review and meta-analysis, respectively. Compared with reference, fathers aged 25 to 29, young fathers (< 20 years) could increase the risk of urogenital abnormalities (OR: 1.50, 95 % CI: 1.03-2.19) and chromosome disorders (OR: 1.38, 95 % CI: 1.12-1.52) in their offsprings; old fathers (≥ 40 years) could increase the risk of cardiovascular abnormalities (OR: 1.10, 95 % CI: 1.01-1.20), facial deformities (OR: 1.08, 95 % CI: 1.00-1.17), urogenital abnormalities (OR: 1.28, 95 % CI: 1.07-1.52), and chromosome disorders (OR: 1.30, 95 % CI: 1.12-1.52).

CONCLUSIONS

Our study indicated that paternal age is associated with a moderate increase in the incidence of urogenital and cardiovascular abnormalities, facial deformities, and chromosome disorders.

METHODS

PubMed, Web of Science, the Cochrane Library, and Embase were searched for relevant literatures from 1960 to February 2020. The systematic review follows PRISMA guidelines. Relevant meta-analyses were performed.

Evaluation of interactive effects between paternal alcohol consumption and paternal socioeconomic status and environmental exposures on congenital heart defects

BACKGROUND

While the maternal risk factors on congenital heart defects (CHDs) have often been assessed, paternal contribution to CHDs, especially the joint effects of paternal risk factors on CHDs remain unknown. This study examined the major impacts of paternal alcohol consumption and its interaction (on multiplicative and additive scales) with paternal socioeconomic status (SES) and environmental exposures on CHDs in China.

METHODS

A population-based case-control study involving 4,726 singleton CHDs cases and 4,726 controls (without any malformation and matched on hospital, gender, and gestational age) was conducted in Guangdong, China, 2004-2014. Information on parental demographics, behavioral patterns, disease/medication, and environmental exposures (3 months before pregnancy) was collected through face-to-face interviews. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) while controlling for all parental factors.

RESULTS

Paternal alcohol consumption was associated with an increased OR of CHDs (adjusted OR = 2.87, 95% CI: 2.25-3.65). Additionally, paternal smoking, industry occupation, organic solvent contact, virus infection and antibiotic use, living in rural areas, low household income, and migrant status were significantly associated with CHDs (ORs ranged: 1.42-4.44). Significant additive or multiplicative interactions were observed between paternal alcohol consumption and paternal smoking, industrial occupation, and low income on any CHDs (interaction contrast ratio [ICR] = 4.72, 95% CI: 0.96-8.47] and septal defects (ICRs ranged from 2.04 to 2.79, p < .05).

CONCLUSIONS

Paternal alcohol consumption and multiple paternal factors were significantly associated with CHDs in China. Paternal smoking and low SES factors modified paternal alcohol consumption-CHDs relationships. Further studies are needed to confirm these findings.

Paternal age is affected by genetic abnormalities, perinatal complications and mental health of the offspring

Infertility and fecundity problems concern 10-18% of partners in their reproductive years compromising around one million females and males in Poland. Research and analysis of factors that affect male fertility are limited, especially, regarding the age of the father and determining the age at which quality of semen decreases. Age of the father has greater impact than maternal age, on cases of sporadic autosomal dominant congenital diseases such as Apert, Crouzon, Pfeiffer, Noonan and Costello syndromes, multiple endocrine neoplasia (types 2A and 2B) and achondroplasia. However, there are only a few reports taking paternal advanced age into consideration for pre-mature birth, low Apgar scores or admission to a neonatal intensive care department. Paternal age increases the frequency of congenital diseases such as heart malformations as well as oral, palate and lip cleft. Moreover, mental disorders (autism, schizophrenia, bipolar disorder, low IQ level as well as ADHD) also occur more frequently in advanced father's age. Advanced paternal age is defined differently in every research. It depends on disorders in offspring we are talking about. Paternal age has an impact on child's health and development and it is as significant as maternal age, when it comes to reproductive matters.

The non-genetic paternal factors for congenital heart defects: A systematic review and meta-analysis

Background

Advances have been made in identifying genetic etiologies and maternal risk factors of congenital heart defects (CHDs), while few literatures are available regarding paternal risk factors for CHDs. Thus, we aim to conduct a meta‐analysis and systematic review about the non‐genetic paternal risk factors for CHDs.

Methods

We searched the PubMed, MEDLINE, and Cochrane Library online databases and identified 31 studies published between 1990 and 2018 according to the inclusion criteria. Paternal risk factors were divided into subgroups, and summarized odd ratios (OR) were calculated.

Results

Paternal age between 24 and 29 years decreased the risk of CHDs in the offspring (OR = 0.90 [0.82, 0.98]), while paternal age ≥ 35 years old increased the risk of CHDs (35‐39 years old: OR = 1.14 [1.09, 1.19], and ≥ 40 years: OR = 1.27 [1.14, 1.42]). Paternal cigarette smoking increased the risk of CHDs in a dose‐dependent way. Paternal wine drinking (OR = 1.47 [1.05, 2.07]) and exposure to chemical agents or drugs (OR = 2.15 [1.53, 3.02]) also increased the risk of CHDs. Some specific paternal occupations were also associated with increased risk for CHDs or CHD subtypes including factory workers, janitors, painters, and plywood mill workers.

Conclusions

This meta‐analysis and systematic review suggested that advanced paternal age, cigarette smoking, wine drinking, exposure to chemical agents or drugs and some specific occupations were associated with an increased risk of CHDs. More measures should be taken to reduce occupational and environment exposures. At the same time, fertility at certain age and establishment of healthy life habits are strongly recommended.

Association of NKX2-5, GATA4, and TBX5 polymorphisms with congenital heart disease in Egyptian children

Background

Several genes encoding transcription factors are known to be the primary cause of congenital heart disease. NKX2‐5 and GATA4 were the first congenital heart disease–causing genes identified by linkage analysis. This study designed to study the association of five single–nucleotide variants of NKX2‐5, GATA4, and TBX5 genes with sporadic nonsyndromic cases of a congenital cardiac septal defect in Egyptian children.

Methods

Venous blood samples from 150 congenital heart disease children (including a ventricular septal defect, atrial septal defect, tetralogy of Fallot, and patent ductus arteriosus) and 90 apparently healthy of matched age and sex were studied by polymerase chain reaction followed by direct sequencing in order to study two single–nucleotide variants of NKX2‐5 (rs2277923, rs28936670), two single–nucleotide variants of GATA4 (rs368418329, rs56166237) and one single–nucleotide variant TBX5 (rs6489957). The distribution of genotype and allele frequency in the congenital heart diseases (CHD) group and control group were analyzed.

Results

We found different genotype frequencies of the two variants of NKX2‐5, as CT genotype of rs2277923 was present in 58% and 36% in cases and control respectively, and TT genotype present in 6% of the cases. Also regarding missense variant rs28936670, heterozygous AG presented in 82% of the cases. Also, we observed a five prime UTR variant rs368418329, GT (42% of the cases) and GG (46% of the cases) genotypes showed the most frequent presentation in cases. While regarding a synonymous variant rs56166237, GT and GG were the most presented in cases (41.4%, 56% respectively) in contrast to control group (20%, 1.7% respectively). Also, a synonymous variant in TBX5, the distribution of genotype frequency was significantly different between the CHD group and control group. CT genotype of TBX5 ‐rs6489957 was found in 12 ASD, 24 VSD, six PDA, three aortic coarctation and nine fallot that represent 42% of the cases.

Conclusions

Significantly higher frequency of different allelle of five variants was observed in cases when compared to the control group, with significant risky effect for the development of septal defect. In addition to two polymorphisms of NKX2‐5 (rs2277923, rs28936670) variant in the cardiac septal defect, two variants in GATA4 (rs368418329, rs56166237) and one variant in TBX5 (rs6489957) seem to have a role in the pathogenesis of congenital heart disease.

The role of diagnostic cardiac catheterization for children with congenital heart diseases: local experience

Introduction

Despite the development of non-invasive tools of investigations for congenital heart diseases (CHDs), still the role of diagnostic cardiac catheterization (DCC) cannot be undermined. The study aimed to analyze the clinical profile of indicated CHDs cases at our center for DCC to evaluate the contribution of DCC in patients’ management plans.

Material and methods

The study checked files of cases performed DCC between 2011 and 2012 at the pediatric catheterization unit of Alexandria University Children’s Hospital by the same operator. Demographic, laboratory and hemodynamic data were collected and analyzed.

Results

Files of 61 children were included in the study. They were grouped into: group I (GI) (n = 25) with pulmonary hypertension (PH), and group II (GII) (n = 36) cases with obstructive pulmonary artery diseases. For the PH group, ventricular septal defect (VSD) was the most common (55%), and patients’ outcome plans were based on angiography – operable subgroup GI-A: (84%) (n = 21) and non-operable (16%) GI-B: (4% inoperable, 12% recommended for sildenafil). GI-B cases were significantly older, with higher PVRI and PVRI/SVRI (3.62, 0.68, p = 0.002) compared to GI-A (0.89, 0.23, p = 0.002, respectively). For group II, tetralogy of Fallot (TOF) was predominant (60%) among the disease spectrum, and the McGoon ratio ranged from 0.7 to 3.2 (median: 1.8). Outcome for GII: 63% operable, 25% shunt, 12% stent. Only pulmonary atresia cases showed a significant difference in the unmatched plans between echocardiography and catheterization reports (χ² = 7.438, p = 0.023).

Conclusions

Diagnostic cardiac catheterization had a positive contribution for determination of the management plans for more than 84% of cases. The utility of pediatric cardiac catheterization in diagnosis should be adjusted according to the local needs of every cardiac center.

Effects of Prenatal PM10 Exposure on Fetal Cardiovascular Malformations in Fuzhou, China: A Retrospective Case-Control Study

BACKGROUND

Maternal exposure to ambient air pollution has been associated with an increased risk of congenital heart defects in offspring; however, the results are inconsistent.

OBJECTIVES

We investigated whether there is an association between prenatal exposure to particulate matter with diameter ≤10μm (PM₁₀) during early pregnancy and fetal cardiovascular malformations.

METHODS

The gravidae from a hospital-based case–control study in Fuzhou, China, during 2007–2013 were assigned 10-d or 1-mo averages of daily PM₁₀ using an air monitor–based inverse distance weighting method during early pregnancy. A total of 662 live-birth or selectively terminated cases and 3,972 live-birth controls were enrolled. The exposure was considered as a categorical variable. A multivariable logistic regression model was constructed to quantify the adjusted odds ratios (aORs) of the exposure to PM₁₀ and the risks of fetal cardiovascular malformations.

RESULTS

PM₁₀ levels were positively associated with the risks of atrial septal defect (aORs ranging from 1.29 to 2.17), patent ductus arteriosus [aORs = 1.54, 1.63; 95% confidence intervals (CIs): 1.17, 2.23; 1.06, 3.24], overall fetal cardiovascular malformations (aOR = 1.28; 95% CI: 1.03, 1.61), ventricular septal defect (aOR = 1.19; 95% CI: 1.00, 1.43), and tetralogy of Fallot (aOR = 1.44; 95% CI: 1.01, 2.19) in the various observed periods scaled by 10 d or 1 mo in the first and second gestation months. The strongest associations were observed for exposure to PM₁₀ in the second quartile, whereas the associations were attenuated when higher concentrations of PM₁₀ in the third and fourth quartiles of the exposure were evaluated. No correlations of PM₁₀ levels with these cardiovascular malformations in the other time periods of gestation were observed.

CONCLUSIONS

Our findings suggest some positive associations between maternal exposure to ambient PM₁₀ during the first two months of pregnancy and fetal cardiovascular malformations. https://doi.org/10.1289/EHP289.

Genetics of consanguinity and inbreeding in health and disease

CONTEXT

Inbreeding increases the level of homozygotes for autosomal recessive disorders and is the major objective in clinical studies. The prevalence of consanguinity and the degree of inbreeding vary from one population to another depending on ethnicity, religion, culture and geography. Global epidemiological studies have revealed that consanguineous unions have been significantly associated with increased susceptibility to various forms of inherited diseases.

OBJECTIVE

The study aimed to determine the role of consanguinity in human health and to highlight the associated risks for various diseases or disorders.

METHODS

PubMed and Google Scholar search engines were used to explore the published literature on consanguinity and its associated risks using the key words "consanguinity", "prevalence", "inbreeding depression", "coefficient of inbreeding", "child health", "mortality", "human health", "homozygosity" and "complex diseases" in different combinations. The studies were screened for eligibility on the basis of their epidemiological relevance.

RESULTS

This comprehensive assessment highlights the deleterious consequences in populations with a higher prevalence of consanguinity among different countries worldwide.

CONCLUSIONS

To avoid the inbreeding load there is the need to improve socioeconomic and educational status and to increase public awareness of reproductive health and anticipated deleterious effects. Pre-marital and pre-conception counselling of consanguineous populations should be an integral part of health policy to train people and make people aware of its harmful consequences. Furthermore, runs of homozygosity (ROH) and whole-exome sequencing (WES) are useful tools in exploring new genomic signatures for the cause of inbreeding depression.

The prevalence of congenital heart defects in infants with cholestatic disorders of infancy: a single-centre study

BACKGROUND

There is deficiency of data about congenital heart defects (CHDs) in cholestatic disorders of infancy other than Alagille syndrome (AGS). We aimed to define the prevalence and types of CHDs in infants with various causes of cholestatic disorders of infancy.

METHODS

This cross-sectional study was conducted on 139 infants presenting with cholestasis whether surgical or non-surgical. The study was carried out at the Pediatric Hepatology Unit, Cairo University Children's Hospital, Egypt. Full examination and investigations were done in an attempt to reach an aetiologic diagnosis for cholestasis, in addition to a comprehensive echocardiographic study.

RESULTS

The age at the onset of cholestasis ranged from 1 day to 7 months. Males constituted 61.2%. Biliary atresia (BA) was diagnosed in 39 patients (28%), AGS in 16 patients (11.5%), 27 patients had miscellaneous diagnoses and 57 cases had indeterminate aetiology. CHDs were detected in 55 patients (39.5%). Shunt lesions were detected in 24 patients (43.6%), pulmonary stenosis in 18 patients (32.7%) and combined lesions in 9 patients (16.4%). Three patients (5.5%) had abnormal cardiac situs. Only seven patients had clinical presentation suggestive of CHD. CHDs were detected in 14 patients with BA (35.9%), 15 patients with AGS (93.7%) and 26 patients in the remaining group (30.9%).

CONCLUSION

CHDs are not uncommon among cholestatic infants and are mostly asymptomatic. Echocardiographic examination of cholestatic infants is recommended particularly for patients with BA before undergoing hepatic portoenterostomy as presence of CHD may impact the anaesthetic planning and affect the outcome of hepatobiliary surgery.

Parental perceptions of congenital cardiovascular malformations in their children

We assessed parental attitudes towards congenital cardiovascular malformations in their children in a cross-sectional study in Egypt. Parents face many problems related to concerns about their child's prognosis, but these associations with parental stress have never been evaluated in Egypt or examined in relation to religiosity in a predominantly Muslim society. Accordingly, we conducted interviews in Cairo with mothers of 99 sequential infants born with conotruncal heart malformations (cases) and 65 mothers of age-matched controls. The survey assessed healthcare access and usage, knowledge of congenital cardiovascular malformations, religiosity, the Locus of Control Scale, and the Parenting Stress Index. Results showed that 45% of the mothers of cases had correct knowledge about their child's diagnosis; 85% were satisfied with the clinical care; and 79% reported that the cost of care was burdensome. Compared with parents of cases, parents of controls were more likely to report stress overall and all its subscales. Regarding belief about locus of control over health, God as a determining factor was given the highest endorsement. Mothers in the congenital cardiovascular malformations group reported a higher level of parental locus of control than did those in the control group. The correlations between stress and locus of control were stronger in the control than in the case group. Religiosity was related neither to stress nor to locus of control. Future studies can explore the roles that personal, familial, and societal factors play in exacerbating or reducing stress levels among parents of sick children, particularly in developing countries where economic pressures are acute.

Paediatric and congenital cardiac surgery in emerging economies: surgical 'safari' versus educational programmes

To attract the interest of all people potentially involved in humanitarian activities in the emerging economies, in particular giving attention to the basic requirements of the organization of paediatric cardiac surgery activities, the requirements for a successful partnership with the local existing organizations and the basic elements of a patient-centred multidisciplinary integrated approach. Unfortunately, for many years, the interventions in the low and middle income countries were largely limited to short-term medical missions, not inappropriately nicknamed 'surgical safari', because of negative general and specific characteristics. The negative aspects and the limits of the short-term medical missions can be overcome only by long-term educational programmes. The most suitable and consistent models of long-term educational programmes have been combined and implemented with the personal experience to offer a proposal for a long-term educational project, with the following steps: (i) site selection; (ii) demographic research; (iii) site assessment; (iv) organization of surgical educational teams; (v) regular frequency of surgical educational missions; (vi) programme evolution and maturation; (vii) educational outreach and interactive support. Potential limits of a long-term educational surgical programme are: (i) financial affordability; (ii) basic legal needs; (iii) legal support; (iv) non-profit indemnification. The success should not be measured by the number of successful operations of any given mission, but by the successful operations that our colleagues perform after we leave. Considering that the children in need outnumber by far the people able to provide care, in this humanitarian medicine there should be plenty of room for cooperation rather than competition. The main goal should be to provide teaching to local staff and implement methods and techniques to support the improvement of the care of the patients in the long run. This review focuses on the organization of paediatric cardiac activities in the emerging economies, but 'the less privileged parts of the world' can be anywhere, not necessarily limited to economic constraints. Lack of diversity because of social, intellectual, educational and professional growth, the last consisting in cultural stagnation, is responsible for the lack of scientific progress and development.

Paternal age and offspring congenital heart defects: a national cohort study

Paternal age has been associated with offspring congenital heart defects (CHDs), which might be caused by increased mutations in the germ cell line because of cumulated cell replications. Empirical evidences, however, remain inconclusive. Furthermore, it is unknown whether all subtypes of CHDs are affected by paternal age. We aimed to explore the relationship between paternal age and the risk of offspring CHDs and its five common subtypes using national register data in Denmark. A total of 1 893 899 singletons born in Denmark from 1977 to 2008 were included in this national-based cohort study. Cox’s proportion hazards model with robust sandwich estimate option was used to estimate the hazards ratio (95% confidence interval) for the associations between paternal age and all CHDs, as well as subtypes of CHDs (patent ductus arteriosus (PDA), ventricular septal defect (VSD), atrial septal defect (ASD), tetralogy of fallot (TOF) and coarctation of the aorta (CoA)). We did not observe an overall association between paternal age and offspring CHDs. However, compared to the paternal age of 25–29 years, paternal age of older than 45 years was associated with a 69% increased risk of PDA (HR45+ = 1.69, 95%CI:1.17–2.43). We observed similar results when subanalyses were restricted to children born to mothers of 27–30 years old. After taking into consideration of maternal age, our data suggested that advanced paternal age was associated with an increased prevalence of one subtype of offspring congenital heart defects (CHDs), namely patent ductus arteriosus (PDA).

Maternal socioeconomic status and the risk of congenital heart defects in offspring: a meta-analysis of 33 studies

Background

We conducted this meta-analysis to address the open question of a possible association between maternal socioeconomic status and congenital heart defects (CHDs).

Methods

We searched MEDLINE and EMBASE from their inception to January 1, 2014 for case-control and cohort studies that assessed the association between maternal socioeconomic status and the risk of CHDs. Study-specific relative risk estimates were polled according to random-effect or fixed-effect models.

Results

From 3343 references, a total of 31 case-control studies and 2 cohort studies were enrolled in this meta-analysis, including more than 50,000 cases. We observed that maternal educational attainment, family income and maternal occupation were negatively associated with an 11% (pooled RR = 1.11, 95% CI: 1.03, 1.21), 5% (pooled RR = 1.05, 95% CI: 1.01, 1.09) and 51% (pooled RR = 1.51, 95% CI: 1.02, 2.24) increased risk of CHDs, respectively. In a subgroup analysis by geographic region, the results were inconsistent for the European region (RR = 1.29, 95% CI: 0.99–1.69) and USA/Canada region (RR = 1.06, 95% CI: 0.97, 1.16) in maternal educational attainment.

Conclusion

In summary, this meta-analysis suggests that a lower degree of maternal socioeconomic status is modestly associated with an increased risk of CHDs. However, further investigations are needed to confirm the association.

Nongenetic risk factors and congenital heart defects

Advances have been made in identifying genetic etiologies of congenital heart defects. Through this knowledge, preventive strategies have been designed and instituted, and prospective parents are counseled regarding their risk of having an affected child. Great strides have been made in genetic variant identification, and genetic susceptibility to environmental exposures has been hypothesized as an etiology for congenital heart defects. Unfortunately, similar advances in understanding have not been made regarding strategies to prevent nongenetic risk factors. Less information is available regarding the potential adverse effect of modifiable risk factors on the fetal heart. This review summarizes the available literature on these modifiable exposures that may alter the risk for congenital heart disease. Information regarding paternal characteristics and conditions, maternal therapeutic drug exposures, parental nontherapeutic drug exposures, and parental environmental exposures are presented. Factors are presented in terms of risk for congenital heart defects as a group. These factors also are broken down by specific defect type. Although additional investigations are needed in this area, many of the discussed risk factors present an opportunity for prevention of potential disease.

Political challenges to biomedical universalism: kidney failure among Egypt's poor

Why do patients in need of kidney transplants in Egypt decline offers of kidney donation from their family members out of reluctance to cause them harm? Is it not universally the case that a living donor could live in complete health with a single remaining kidney? To address this conundrum, I discuss a case study from Egypt, in which patients reveal social, political, and environmental stresses on organ function that challenge the presumed universal efficacy and safety of kidney transplantation. I demonstrate that the biomedical position on the tolerable risks posed to the living donor is conditional and premised on particular social and historical contingencies that can be misaligned when applied in other contexts. Drawing on the work of Margaret Lock, I illustrate how analytical contributions of medical anthropologists can shed light on a political and public health impasse about how to legally regulate organ transplantation in Egypt.

Risk Factors of Congenital Heart Diseases: A Case-Control Study inNorthwest Iran

INTRODUCTION

Congenital heart diseases are of immense importance and also a high prevalence. Contributing factors to developing these defects have not been abundantly studied. Therefore, the current study was conducted aiming at determining the effective factors on Congenital Heart Disease (CHD) in newborn infants of Northwest Iran.

METHODS

A case-control study was carried out in North-West of Iran from 2002 to 2012 and a total of 473 infants entered the study. Required data were obtained through check lists completed by the information of hospital records and interview with mothers of 267 newborn infants with CHD together with medical records of mothers as the case group, and 206 medical records of healthy infants at the same period all together with those of their mothers as the control group. The obtained data were statistically analyzed using descriptive statistical methods, T-test, Spearman's correlation coefficient, and Multi-variable Logistic Regression Model (OR with 95% CI), using SPSS.19. In the present study, P value less than 0.05 was considered statistically significant.

RESULTS

Based on the results of univariable analyses, the number of previous cesarean sections, past medical history of diseases, gestational age (GA), fetal weight at birth, diastolic blood pressure, fetal heart rate, pulse rate, fetal hemoglobin and hematocrit levels, and fetal head circumference at birth have significant relationship with incidence of congenital abnormalities (P<0.05). Family history, past cesarean sections history, past medical history and GA had significant relationship with CHD incidence.

CONCLUSION

Based on the results of present study, in order to control and reduce the cases of CHD, it is crucial to make proper decisions and implement policies for reducing cesarean cases, lowering consanguineous marriages, providing proper pre-marriage counseling, prompt treatment of mothers' illnesses, improving pregnancy health care and mothers' health status for the purpose of better well-being of newborn infants.

Consanguinity and the risk of congenital heart disease

Consanguineous unions have been associated with an increased susceptibility to various forms of inherited disease. Although consanguinity is known to contribute to recessive diseases, the potential role of consanguinity in certain common birth defects is less clear, particularly since the disease pathophysiology may involve genetic and environmental/epigenetic factors. In this study, we ask whether consanguinity affects one of the most common birth defects, congenital heart disease, and identify areas for further research into these birth defects, since consanguinity may now impact health on a near-global basis. A systematic review of consanguinity in congenital heart disease was performed, focusing on non-syndromic disease, with the methodologies and results from studies of different ethnic populations compared. The risks for congenital heart disease have been assessed and summarized collectively and by individual lesion. The majority of studies support the view that consanguinity increases the prevalence of congenital heart disease, however, the study designs differed dramatically. Only a few (n = 3) population-based studies that controlled for potential sociodemographic confounding were identified, and data on individual cardiac lesions were limited by case numbers. Overall the results suggest that the risk for congenital heart disease is increased in consanguineous unions in the studied populations, principally at first-cousin level and closer, a factor that should be considered in empiric risk estimates in genetic counseling. However, for more precise risk estimates a better understanding of the underlying disease factors is needed.

Gestational and family risk factors for carriers of congenital heart defects in southern Brazil

BACKGROUND

Congenital heart disease (CHD) is a serious threat to public health. Despite this, its etiology is poorly understood and few cardiac teratogens have been defined. The aim of the present study was to identify gestational and family risk factors for CHD in a sample of patients from a pediatric hospital in southern Brazil.

METHODS

A prospective and consecutive sample from subjects with or without CHD, hospitalized at a pediatric intensive care unit, was enrolled. All patients with CHD underwent a GTG-banding karyotype. Chromosomal abnormalities were observed in 47 subjects (15.8%), and these were excluded from the study. The final sample consisted of 250 CHD subjects and 303 controls.

RESULTS

After statistical analysis, using logistic regression, the variables age, rural location, gestational loss, use of anti-hypertensive medication, antibiotics and alcohol in the first trimester of pregnancy were all independently associated with CHD. These results were similar to those of some studies and different from others. It should be noted, however, that, for several variables, the data in the literature as well as the present study were insufficient to determine risk.

CONCLUSIONS

Some differences found may be explained by genetic factors and sociocultural diversity. In contrast, because CHD consists of a heterogeneous group of lesions, the etiology may vary. The standardization of research data and classification of methods for future studies are essential.

Ambient air pollution and congenital heart disease: a register-based study

Maternal exposure to ambient air pollution has increasingly been linked to adverse pregnancy outcomes. The evidence linking this exposure to congenital anomalies is still limited and controversial. This case-control study investigated the association between maternal exposure to ambient particulate matter with aerodynamic diameter less than 10 μm (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxide, nitric oxide (NO), ozone (O(3)), and carbon monoxide (CO) and the occurrence of congenital heart disease in the population of Northeast England (1993-2003). Each case and control was assigned weekly average (weeks 3-8 of pregnancy) of pollutant levels measured by the closest monitor to the mother's residential postcode. Using exposure as both continuous and categorical variables, logistic regression models were constructed to quantify the adjusted odds ratios of exposure to air pollutants and the occurrence of each outcome group. We found exposure to CO and NO to be associated with ventricular septal defect and cardiac septa malformations. CO was also associated with congenital pulmonary valve stenosis and NO with pooled cases of congenital heart disease and tetralogy of Fallot. Findings for SO(2), O(3) and PM(10) were less consistent.

Association between maternal exposure to ambient air pollution and congenital heart disease: A register-based spatiotemporal analysis

Recent studies have linked maternal exposure to air pollution with a range of adverse pregnancy outcomes. However, the available evidence linking this exposure to congenital anomalies is still limited and controversial. The present case-control study tested the hypothesis that maternal exposure to ambient black smoke and sulfur dioxide is a risk factor for the occurrence of congenital heart disease. The authors used registry-based data on congenital heart disease for the population of the northeast of England in 1985-1996. A 2-stage spatiotemporal model was developed to predict weekly black smoke and sulfur dioxide levels at each maternal place of residence. Controls were frequency-matched to cases by year of birth (control-to-case ratio of 4:1). Two sets of analyses were performed, using predicted mean values of exposure and 1,000 simulated scenarios of exposure. The analyses were adjusted for birth year, socioeconomic status, infant sex, season of conception, and degree of urbanity. The authors found a weak association between maternal exposure to black smoke and congenital malformations of cardiac chambers and connections only when using exposure as a continuous variable. When the authors used quartiles of exposure, odds ratios did not show a dose-response relation for consecutive quartiles. For sulfur dioxide, the results were not indicative of any association.

Consanguinity in Qatar: knowledge, attitude and practice in a population born between 1946 and 1991

From March 2007 to March 2008 a cross-sectional study was conducted in Qatar to estimate the prevalence of consanguinity among Qataris and to assess their knowledge of the risks and their attitudes towards the practice. A secondary objective was to test the acceptability of sixteen Likert-style questions within the Qatari population. Face-to-face interviews using a 70-item structured questionnaire were conducted by three native Arabic-speaking medical students with 362 Qatari employees. Where consanguinity existed between the employee's parents, a diagram of the consanguinal relationship (phylogram) was completed. The response rate was 93%. By phylogram, 22% of participants reported a cousin relationship between their parents (consanguinal relationship) and another 15% reported that their parents were from the same tribe (affinal relationship). With respect to their own marital decision, 68% of the respondents had been married at least once. By phylogram, 35% of these reported a consanguineous relationship (first marriage), 9% reported only an affinal relationship and 56% reported that they were not married to a blood relative. Results on the sixteen Likert-style attitude questions were stratified by consanguinity status of parents and of self. In the stratification by consanguinity status of parents the top five attitudes differed by group but there appeared to be more similarity between the consanguinal and only tribal groups. Attitudinal results were stratified by sex. Results showed that the males had a stronger belief in several of the attitudes than females with the exception of causation of genetic abnormalities and health problems. The phylogram was shown to collect more detailed and explicit data than hard-coding. With respect to knowledge, the results showed that knowledge was imperfect with high proportions of participants not knowing that consanguinity has been implicated in autosomal recessive diseases such as thalassaemia, inborn errors of metabolism, deafness, anomalies of the extremities and specific congenital heart defects. Additionally, a sizeable proportion of the participants did not know that a more distant cousin marriage (e.g. third cousin) theoretically could be a less genetically risky choice to potential offspring than a closer cousin marriage (half-first cousin). These results indicate that more effort needs to be made in developing public health strategies to improve the population's understanding of the cost-benefit analysis involved in contracting consanguineous marriages given the goal of healthy offspring.

Environmental risk factors for congenital heart disease in the Shandong Peninsula, China: a hospital-based case-control study

BACKGROUND

In China, and in Shandong province, the proportionate contribution of birth defects to infant mortality has increased, and congenital heart disease (CHD) is now the most common cause of birth defects. The cause of approximately 90% of cases of congenital heart disease is multifactorial. Little is known about modifiable environmental risk factors or regional differences. We investigated putative environmental risk factors for congenital heart disease in the Shandong province of China in order to improve prevention of CHD.

METHODS

We conducted a hospital-based 1:2 matched case-control study of 164 patients with congenital heart diseases and 328 controls, all of whom were retrospectively interviewed. Univariate and multivariate analyses were conducted to identify environmental risk factors for CHD.

RESULTS

The environmental risk factors associated with CHD were mother's education level (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.15-0.67), neonatal asphyxia or hypoxia (OR, 3.74; 95% CI, 1.25-11.18), number of previous pregnancies (OR, 2.68; 95% CI, 1.44-4.97), maternal upper respiratory tract infection (OR, 4.12; 95% CI, 1.56-10.85), maternal infection (OR, 7.98; 95% CI, 2.14-29.72), maternal B-mode ultrasound examination (OR, 4.05; 95% CI, 1.48-11.08), and maternal mental stress (OR, 3.93; 95% CI, 1.94-7.94) during early pregnancy. No significant interactions were observed among these factors.

CONCLUSIONS

Augmenting maternal mental healthcare, obtaining regular health counseling and testing during pregnancy, preventing upper respiratory tract infections, limiting medication during early pregnancy, offering health promotion and health education to women of childbearing age (especially those with less formal education), and improving obstetric procedures and techniques may lower the occurrence of congenital heart disease.

Congenital cardiac disease and inbreeding: specific defects escape higher risk due to parental consanguinity

AIMS

To test on a large cohort whether parental consanguinity varies among different types of congenitally malformed hearts.

METHODS AND RESULTS

Between 1 May, 1999, and 28 February, 2006, a large cohort of 1585 newly diagnosed cases with non-syndromic congenitally malformed heart was enrolled at the National Register of Paediatric and Congenital Heart Disease, Lebanese Society of Cardiology, Beirut. Another group, made up of 1979 cases referred to the National Register of Paediatric and Congenital Heart Disease, but free of any malformation, and with a rate of consanguinity similar to a recent survey made by UNICEF in Lebanon, was used for the purposes of control. We used the Chi-squared test, and ratio of risk, to compare the groups. Subgroups with first degree cousins, first plus second degree cousins, and any degree of consanguinity, are significantly larger in the cohort with congenitally malformed hearts than in the control cohort, with proportions of 19.4%, 25.7%, and 27.4% versus 14.4%, 20.3%, and 23.9%, respectively. Those with tetralogy of Fallot, valvar aortic stenosis, and atrial septal defect have a significantly higher percentage of consanguineous parents than do the controls. By contrast, this is not the case for those with atrioventricular septal defect and common atrioventricular junction ("atrioventricular canal"), or discordant ventriculo-arterial connections ("transposition"). These differences persist when the types of congenital cardiac defect types are pooled according to presumed embryological processes. Those with hypoplasia of the left heart have increased parental consanguinity, but not the group of various types of discordant ventriculo-arterial connections.

CONCLUSION

Only some types of congenitally malformed hearts have an increased percentage of parental consanguinity, suggesting that those types with no increased risk due to parental consanguinity are determined by genetic factors that are X-linked or exclusively autosomal dominant.

Parental consanguinity increases congenital heart diseases in South India

BACKGROUND

Congenital heart diseases (CHDs) are the commonest single group of congenital abnormalities with a prevalence ranging from 1.0 to 50.89 per 1000 live births in the world population including India, whereas Mysore has a prevalence of 11.08 per 1000 live births. One of the risk factors for the occurrence of CHDs is parental consanguinity, in particular first-cousin marriage between parents.

AIM

The present study examined the role of consanguineous marriages in causing CHDs in Mysore, South India.

SUBJECTS AND METHODS

A total of 144 confirmed CHD cases with an age range of 1 day to 23 years and a control group of 200 families from different localities of Mysore city were considered for the present study. Methods included the establishment of a genetic register and pedigree analysis followed by statistical analysis by logistic regression.

RESULTS

The findings revealed that first-cousin marriages (44.68%) and uncle-niece marriages (46.81%) are equally significant in increasing CHDs. The subtypes of CHDs associated with consanguinity were found to be atrial septal defect (ASD) and patent ductus arteriosus (PDA). These findings emphasize the important role played by segregation of recessive genes in the offspring resulting in the causation of CHDs.

CONCLUSION

Therefore, for every incidence of parental consanguinity, the risk (odds) of birth of a child with CHD increases. There is an urgent need to educate the public on the deleterious effects of inbreeding, especially in India, which has high overall consanguinity.

Influence of consanguinity on the pattern of familial aggregation of congenital cardiovascular anomalies in an outpatient population: studies from the eastern province of Saudi Arabia

BACKGROUND

Familial aggregation of congenital heart disease (CHD) has been well described in different populations, in particular those with a high consanguinity rate. Extensive genetic study of affected families has improved the understanding of basic genetics of different cardiac lesions.

OBJECTIVE

To identify the role of consanguinity as a risk factor among familial cases of CHD in a stable outpatient population of a tertiary care center in the Eastern Province of Saudi Arabia.

METHODS

All familial cases of CHD seen over 5 years (1996-2000) in the Division of Pediatric Cardiology were identified. The presence or absence of parental consanguinity (first cousin marriage) was defined in each of these families.

RESULTS

Ninety-three cases were identified in 37 families. Twenty-three (62%) families resulted from consanguineous marriages. In 4 families where there were 2 marriages, the affected children came from the consanguineous marriage in 3 of these families. Discordant lesions occur only among non-consanguineous cases, while all consanguineous cases were concordant. Five sets of twins of the same sex (one set are monozygotic by DNA analysis) occurred among consanguineous marriages, in 3 of these both twins were affected with the same disease. Affected parents were seen in 2 families with consanguineous marriage and none in the non-consanguineous marriages. The prevalence of dilated cardiomyopathy was much higher among consanguineous cases (26 vs. 2).

CONCLUSIONS

Familial aggregation of congenital heart disease is common in our population. Consanguinity is common in these families, and the distribution of congenital heart disease differs in this subgroup compared to the rest of the familial cases. Further genetic studies of these families may help to shed more light on basic genetics and the specific pathogenetic mechanisms involved.

Paternal age and birth defects: how strong is the association?

BACKGROUND

Although the association between maternal age and the risks of birth defects has been well studied, the evidence from population data linking paternal age with birth defects was limited and inconsistent.

METHODS

We conducted a population-based retrospective cohort study of 5,213,248 subjects from the 1999-2000 birth registration data of the USA. Multiple logistic regressions were used to estimate the independent effect of paternal age on all birth defects and 21 specific defects groups after adjusting for potential confounding of maternal age, race, education, marital status, parity, prenatal care initiation, maternal smoking and alcohol drinking during pregnancy.

RESULTS

A total of 77,514 (1.5%) birth defects were recorded in the study cohort. The adjusted odds ratios were 1.04 (1.01, 1.06), 1.08 (1.04, 1.12), 1.08 (1.02, 1.14) and 1.15 (1.06, 1.24), respectively, for infants born to fathers 30-35, 40-44, 45-49 and over 50 years (test for trend, P = 0.0155), when compared with those infants born to fathers aged 25-29 for any birth defect. Advanced paternal age was associated with increased risks of heart defects, tracheo-oesophageal fistulaoesophageal atresia, other musculoskeletal/integumental anomalies, Down's syndrome and other chromosomal anomalies. Fathers under 25 years of age were also at increased risks of spina bifida/meningocele, microcephalus, omphalocele/gastroschisis and other musculoskeletal/integumental anomalies.

CONCLUSIONS

Infants born to older fathers have a slightly increased risk of birth defects. Young paternal age is also associated with slightly increased risk of several selected birth defects in their offspring. However, given the weak association, paternal age appears to play a small role in the aetiology of birth defects.

Consanguineous marriage and congenital heart defects: a case-control study in the neonatal period

The independent effect of consanguinity on the prevalence of congenital heart defects (CHDs), all and specific types, was investigated in newborns admitted to nine hospitals located in Beirut, Lebanon and members of the National Collaborative Perinatal Neonatal Network (NCPNN). Cases were 173 newborns admitted to the Neonatal Intensive Care Units (NICU) of participating hospitals during the 3-year period from January 1, 2000 to December 31, 2002 and diagnosed during their hospital stay as having one or more CHD. Cases with chromosomal abnormalities were excluded. Cases with more than one CHD were assigned one principal malformation. Controls consisted of a random sample of 865 newborns without a CHD admitted to the NICU during the same period. After controlling for confounders, first cousin consanguinity remained significantly associated with an increased risk of CHD: infants born to first cousin marriages had a 1.8 times higher risk of having a CHD diagnosed at birth compared to those born to unrelated parents (95% CI: 1.1-3.1). In particular, first-cousin marriage was a significant risk factor for ventricular septal defect (VSD), atrial septal defect (ASD), hypoplastic left heart (HLH), and single ventricle (SV). No association was found with d-transposition of the great arteries, coarctation, pulmonary atresia (PA), atrioventricular septal defect (AVSD), and tetralogy of Fallot (TOF). The results of this study suggest a familial factor in the multifactorial etiology of CHDs. Additional epidemiologic and family-based genetic studies are needed to understand the complex cause of CHDs.

Congenital heart disease in a population of dizygotic twins: an echocardiographic study

BACKGROUND

Congenital heart disease (CHD) is the most common malformation in the fetal and neonatal period but little is known about its cause. The distribution analysis of CHD in dizygotic twins could provide a useful tool to evaluate the role of genetic and environmental factors in the development of CHD. Dizygotic twins are siblings with different genes, growing together in the same womb.

AIM OF STUDY

To investigate the occurrence of CHD in a large sample of dizygotic twins of nonconsanguineous healthy parents, comparing the data from non-twin patients.

METHODS

From January 1999 to December 2002, we enrolled 1743 CHD patients with, at least 1 sibling, and 66 pairs of dizygotic twins, referred to our tertiary center. The diagnosis of CHD was based on clinical and echocardiographic evaluation.

RESULTS

Considering only the sibling nearest in age for each non-twin patient the recurrence was 67/1743 (3.8%). Among these 67 patients, 35 (52.2%) had a sibling with the same or similar CHD. Conversely, considering all 1886 siblings, recurrence of CHD in the non-twin group was 70/1743 (4%). Of the 70 patients, 36 (36/70, 51.4%) had a sibling with the same suspected pathogenic mechanism of CHD. In 9/66 pairs of twins (13.6%), both siblings had a CHD. In the nine pairs of twins in whom both siblings had a CHD, the percentage of concordance (based on the suspected pathogenic mechanism) for CHD was 100% (p<0.05).

CONCLUSIONS

Our findings suggest that the higher recurrence and concordance of CHD found in dizygotic twins could depend on some poorly identified environmental risk during the pregnancy.

Familial recurrence of congenital heart disease in patients with ostium secundum atrial septal defect

AIMS

Ostium secundum atrial septal defect (osASD) is one of the most common cardiac malformations. Few data are available on the familial recurrence of congenital heart disease (CHD), in particular, in a large group of patients with isolated osASD. The aim is to investigate the familial recurrence of CHD in up to third-degree relatives from a large sample of consecutively enrolled patients with osASD, taking into account the influence of degree of relatedness (as number of relatives).

METHODS AND RESULTS

From January 1998 to December 2002, we enrolled 583 patients with osASD and 408 healthy subjects, referred to our tertiary centre. We hypothesized that a positive family history required at least one relative with CHD to constitute a risk factor. In this model of analysis, the null hypothesis is a similar familial history between cases and controls. Among 583 patients with osASD, 109 (19%) had at least one relative with CHD. Among the 408 healthy subjects studied, only 23 (6%) had a family history of CHD. A familial recurrence of CHD was demonstrated in 72 of 312 (23%) patients with isolated osASD and in 37 of 271 (13.6%) patients with non-isolated osASD. Familial recurrence of isolated osASD was demonstrated in 22 of 312 patients (7%) with an isolated osASD and only in six of 271 patients (2.2%) with non-isolated osASD. The familial recurrence risk of isolated osASD in patients with isolated osASD was higher in sibs, especially in sisters (33.3%).

CONCLUSION

This study underscores the role of genetic factors in the determination of CHD, particularly osASD. Our results could represent the basis for further studies to calculate a 'value of family history' to adapt the familial recurrence to the real size of each family group. In this way, we could select families with a 'tendency' to develop CHD, particularly osASD. In these families, we could analyse the genetic pattern to establish abnormalities and the bases of CHD.

Parental consanguinity and congenital heart malformations in a developing country

The association between isolated congenital heart defects and consanguinity was examined in 759 Lebanese patients with different types of congenital heart malformations. The subjects were patients of the Children's Cardiac Registry Center (CCRC) at the American University of Beirut Medical Center. The proportion of first-cousin marriages among cardiac subjects was compared to that of the National Collaborative Perinatal Neonatal Network (NCPNN), after adjusting for the subjects' geographic distribution, and to the highest proportion reported by NCPNN. In general, the proportion of overall parental consanguinity and first-cousin matings among CCRC subjects (34.7 and 20.2%, respectively) were significantly higher than the highest proportion of first-cousin marriages reported by NCPNN (Bekaa subjects; 13.2%) (P < 0.0001). Comparison with the NCPNN-adjusted first-cousin mating proportion revealed a significantly increased rate of consanguinity in all categories of cardiac malformations except great vessel and coronary artery lesions (P < 0.05). The following lesions were significantly associated with increased parental consanguinity: aortic anomalies (aortic insufficiency, aortic stenosis, bicuspid aortic valve), atrial septal defect, double-outlet right ventricle, pulmonary atresia, patent ductus arteriosus, pulmonic stenosis, tetralogy of Fallot, and ventricular septal defect (P < 0.05). Higher maternal education was the only variable that was negatively correlated with parental consanguinity (P = 0.037). Our study emphasizes the role of homozygous recessive genes in the causation of different types of isolated congenital heart malformations, known to follow a multifactorial pattern of inheritance. There is an urgent need for educating the public on the deleterious effects of inbreeding, especially in developing countries with high overall consanguinity rates and limited financial resources.

Risk factors in congenital heart disease

A case-control study was conducted to investigate the risk factors of congenital heart disease (CHD). The cases were 346 children with CHD who were admitted to a university hospital in Tehran from 1995 to 2000 and controls (n=346) were randomly selected from children without CHD who were admitted during the same period. The medical records of both cases and controls were reviewed. Ten risk factors were studied and found to be more prevalent among cases (47%) than controls (35%, p < 0.005). Extracardiac malformations (OR, 31.1; CI95, 15.9-60.9; p < 0.001) and chromosomal abnormalities (OR, 34.05; CI95, 23.3-49.8; p < 0.001) were significant risk factors for CHD. Dysmorphic syndromes (p < 0.05) and CHD in siblings (p < 0.001) were also significant risk factors. Maternal illness and drug use in the first trimester of pregnancy, maternal history of previous abortions and stillbirths, parental consanguinity, and parental cardiac lesions were not significant risk factors for CHD in offspring. Results suggest that genetic factors more than environmental or reproductive factors can increase the occurrence of cardiac defects.