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.

Commentary on the decision of the American Board of Medical Genetics and Genomics to create a 24-month specialty of Laboratory Genetics and Genomics.

Genet Med 19 3, 294-296.

The Learning Disabilities Network (LeaDNet): using neurofibromatosis type 1 (NF1) as a paradigm for translational research.

Learning disabilities and other cognitive disorders represent one of the most important unmet medical needs and a significant source of lifelong disability. To accelerate progress in this area, an international consortium of researchers and clinicians, the Learning Disabilities Network (LeaDNet), was established in 2006. Initially, LeaDNet focused on neurofibromatosis type 1 (NF1), a common single gene disorder with a frequency of 1:3,000. Although NF1 is best recognized as an inherited tumor predisposition syndrome, learning, cognitive, and neurobehavioral deficits account for significant morbidity in this condition and can have a profound impact on the quality of life of affected individuals. Recently, there have been groundbreaking advances in our understanding of the molecular, cellular, and neural systems underpinnings of NF1-associated learning deficits in animal models, which precipitated clinical trials using a molecularly targeted treatment for these deficits. However, much remains to be learned about the spectrum of cognitive, neurological, and psychiatric phenotypes associated with the NF1 clinical syndrome. In addition, there is a pressing need to accelerate the identification of specific clinical targets and treatments for these phenotypes. The successes with NF1 have allowed LeaDNet investigators to broaden their initial focus to other genetic disorders characterized by learning disabilities and cognitive deficits including other RASopathies (caused by changes in the Ras signaling pathway). The ultimate mission of LeaDNet is to leverage an international translational consortium of clinicians and neuroscientists to integrate bench-to-bedside knowledge across a broad range of cognitive genetic disorders, with the goal of accelerating the development of rational and biologically based treatments.