Congenital heart disease in school children in Lagos, Nigeria: Prevalence and the diagnostic gap.

Congenital heart disease (CHD) in low-and-middle income countries (LMIC) is often characterized by late presentation resulting from inadequate screening and healthcare access in these regions. Accurate estimates of the burden of CHD among school children are often lacking. The objective of this study was to determine the prevalence and distribution of CHD among school children in two communities (urban and semi-urban) in south western Nigeria. Using clinical assessment and portable echocardiography, 4107 school children aged 5 years to 16 years in Lagos, Nigeria, were selected using a multistage sampling procedure and screened for CHD. Diagnosis of CHD was made after echocardiography. Children identified with CHD were referred to a tertiary hospital for appropriate cardiac care. The 4,107 children screened had a mean age of 11.3 ± 2.7 years and 53.7% were females. Twenty seven children had echocardiography-confirmed CHD, representing a prevalence of CHD among school children in Lagos, Nigeria of 6.6 per 1000 children. Acyanotic CHD constituted 96.3% of detected cases. Two children diagnosed with CHD (Tetralogy of Fallot and severe pulmonary valve stenosis respectively) had successful intervention. The prevalence of previously undiagnosed CHD among school children in Lagos Nigeria is substantial and highlights gaps in the health care system and school health programs. Echocardiographic screening of school children provides an opportunity for missed early diagnosis and treatment of CHD and reduces the prevalence of first-diagnosed CHD in adulthood. Therefore, focused clinical examination of school children followed by echocardiography is a strategy that could bridge this diagnostic and treatment gap in CHD.

Echocardiographic screening of 4107 Nigerian school children for rheumatic heart disease.

OBJECTIVE: Echocardiographic screening for Rheumatic Heart Disease (RHD) in Africa has revealed prevalence rates in the range of 0.5-7.4%. There are no recent large population-based studies in Nigeria. The objective of the study was to determine the prevalence of RHD in a large sample of Nigerian school children. METHODS: Using portable transthoracic echocardiography and auscultation, school children aged 5 years to 16 years in Lagos, Nigeria were screened for RHD. Diagnosis was based on the 2012 World Heart Federation echocardiographic criteria. RESULTS: The 4107 children screened had mean age of 11.3 years (SD = 2.6) and 2206 (53.7%) were females. There were 38 children with abnormal echocardiograms, of which 11 (0.27%) showed RHD including two cases of definite RHD giving a prevalence of 2.7/1000 [2.9/1000 in the peri-urban, 2.4/1000 in the urban area). Echocardiography detected RHD 10 times better than auscultation [echocardiography 11 (0.27%) vs. auscultation 1 (0.02%); P = 0.003]. The remaining 27 children with abnormal echocardiograms had congenital heart defects (CHD) giving a prevalence of 6.6/1000 for CHD, a yield higher than for RHD. CONCLUSION: Prevalence of RHD among school children in Lagos, South West Nigeria is low compared to other African countries, possibly due to better access to medical care and antibiotic treatment for infections. Our data provides evidence that RHD prevalence may vary substantially within sub-Saharan Africa, necessitating targeted population-based sampling to better understand disease burden and distribution. Further work is needed to compare within- and between-country RHD prevalence as a basis for programme planning and control efforts.

OBJECTIF: Le dépistage échocardiographique de la cardiopathie rhumatismale (CR) en Afrique a révélé des taux de prévalence compris entre 0,5 et 7,4%. Il n'existe pas de grande étude récente de population au Nigéria. L'objectif de l'étude était de déterminer la prévalence de la CR dans un grand échantillon d'écoliers nigérians. MÉTHODES: A l'aide d'une échocardiographie et d'une auscultation trans-thoraciques portables, des écoliers âgés de 5 à 16 ans de Lagos, au Nigeria, ont été soumis à un dépistage de la CR. Le diagnostic reposait sur les critères échocardiographiques de la Fédération Mondiale du Cœur de 2012. RÉSULTATS: Les 4.107 enfants testés avaient un âge moyen de 11,3 ans (DS = 2,6) et 2.206 (53,7%) étaient de sexe féminin. Il y avait des échocardiogrammes anormaux chez 38 enfants, dont 11 (0,27%) présentaient une CR, y compris deux cas de CR bien définie, donnant une prévalence de 2,7/1000 [2,9/1000 dans les zones périurbaines, 2,4/1000 dans les zones urbaines). L'échocardiographie a détecté une CR 10 fois mieux que l'auscultation [échocardiographie 11 (0,27%) contre auscultation 1 (0,02%); p = 0,003]. Les 27 enfants restants dont les échocardiogrammes étaient anormaux avaient une cardiopathie congénitale (CHD), ce qui donnait une prévalence de 6,6/1.000 pour les cardiopathies congénitales, donnant une prévalence de 6,6/1000, un rendement supérieur à celui de la CR. CONCLUSION: La prévalence de la CR parmi les écoliers à Lagos, dans le sud-ouest du Nigéria, est faible comparée à celle d'autres pays africains, probablement en raison d'un meilleur accès aux soins médicaux et au traitement antibiotique contre les infections. Nos données fournissent des preuves que la prévalence de la CR peut varier considérablement en Afrique subsaharienne, nécessitant un échantillonnage ciblé de la population pour mieux comprendre la charge et la répartition de la maladie. Des études supplémentaires sont nécessaires pour comparer la prévalence de la CR intra- et inter pays en tant que base des efforts de planification et de lutte des programmes.

Down syndrome in diverse populations.

Down syndrome is the most common cause of cognitive impairment and presents clinically with universally recognizable signs and symptoms. In this study, we focus on exam findings and digital facial analysis technology in individuals with Down syndrome in diverse populations. Photos and clinical information were collected on 65 individuals from 13 countries, 56.9% were male and the average age was 6.6 years (range 1 month to 26 years; SD = 6.6 years). Subjective findings showed that clinical features were different across ethnicities (Africans, Asians, and Latin Americans), including brachycephaly, ear anomalies, clinodactyly, sandal gap, and abundant neck skin, which were all significantly less frequent in Africans (P < 0.001, P < 0.001, P < 0.001, P < 0.05, and P < 0.05, respectively). Evaluation using a digital facial analysis technology of a larger diverse cohort of newborns to adults (n = 129 cases; n = 132 controls) was able to diagnose Down syndrome with a sensitivity of 0.961, specificity of 0.924, and accuracy of 0.943. Only the angles at medial canthus and ala of the nose were common significant findings amongst different ethnicities (Caucasians, Africans, and Asians) when compared to ethnically matched controls. The Asian group had the least number of significant digital facial biometrics at 4, compared to Caucasians at 8 and Africans at 7. In conclusion, this study displays the wide variety of findings across different geographic populations in Down syndrome and demonstrates the accuracy and promise of digital facial analysis technology in the diagnosis of Down syndrome internationally. © 2016 Wiley Periodicals, Inc.

Exome Sequencing and Congenital Heart Disease in Sub-Saharan Africa.

BACKGROUND: Congenital heart disease (CHD) is the most common birth defect and affects roughly 1% of the global population. There have been many large CHD sequencing projects in developing countries but none in sub-Saharan Africa. In this exome sequencing study, we recruited families from Lagos, Nigeria, affected by structural heart disease. METHODS: Ninety-eight participants with CHD and an average age of 3.6 years were recruited from Lagos, Nigeria. Exome sequencing was performed on probands and parents when available. For genes of high interest, we conducted functional studies in Drosophila using a cardiac-specific RNA interference-based gene silencing system. RESULTS: The 3 most common CHDs were tetralogy of Fallot (20%), isolated ventricular septal defect (14%), and transposition of the great arteries (8%). Ten percent of the cohort had pathogenic or likely pathogenic variants in genes known to cause CHD. In 64 complete trios, we found 34 de novo variants that were not present in the African population in the Genome Aggregation Database (v3). Nineteen loss of function variants were identified using the genome-wide distribution of selection effects for heterozygous protein-truncating variants (shet). Nine genes caused a significant mortality when silenced in the Drosophila heart, including 4 novel disease genes not previously associated with CHD (UBB, EIF4G3, SREBF1, and METTL23). CONCLUSIONS: This study identifies novel candidate genes and variants for CHD and facilitates comparisons with previous CHD sequencing studies in predominantly European cohorts. The study represents an important first step in genomic studies of CHD in understudied populations. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01952171.

Clinical epidemiology of congenital heart disease in Nigerian children, 2012-2017.

BACKGROUND: Congenital heart diseases (CHDs) affect ~1% of newborns and are a significant cause of morbidity and mortality in children. We present the clinical epidemiology of CHD as seen in a large university medical center in Nigeria. METHODS: Participants were 767 children with echocardiographically confirmed CHD seen over a 5-year period at the Lagos University Teaching Hospital, Nigeria. RESULTS: Clinical presentation was often late with just over half (58.1%) presenting in infancy. The male:female distribution was 1:1. The predominant types of cardiac lesion seen were septal defects (43%), conotruncal defects (23.7%), atrioventricular septal defects (9.8%), and right ventricular outflow tract obstruction (7.3%). Cyanotic CHD was seen in 28.4% of cases and the single most common cyanotic CHD was Tetralogy of Fallot (13.4%). Children with cyanotic CHD were older (p = .002), had more severe lesions (p < .0001) and were more likely to have cardiac intervention (p < .0001). Extracardiac malformations were present in nearly one-third of the children. Syndromes associated with CHD were identified in 15.5% of the children and included Down syndrome (11.9%), congenital rubella syndrome (1.0%), and Marfan syndrome (0.7%). CONCLUSIONS: This study is a large case series of CHD from a single site in sub-Saharan Africa utilizing clinical, epidemiological, and developmental considerations. It provides a rich and up-to-date description of the clinical epidemiology of CHD in Nigerian children while yielding data that could be useful for designing genetic, molecular, and biomarker studies.