Genetic disorders and congenital anomalies in Nigeria: a scoping review.

Nigeria, with its rich cultural and genetic diversity, faces a largely undocumented burden of genetic disorders and congenital anomalies. Understanding this burden is vital for effective healthcare planning and interventions. The aim of this study was to provide a comprehensive overview of the prevalence and geographical distribution of genetic disorders and congenital anomalies in Nigeria based on published evidence. A systematic scoping review was conducted across seven databases using tailored search strategies. Screening was performed in two stages: (1) title and abstract and (2) full text- prior to data extraction and analysis. Prevalence figures were recalculated and standardized as a percentage of live births or individuals. Seventy-eight studies met the inclusion criteria, of which 27 reported at least one genetic disorder. Hemoglobinopathies–particularly sickle cell disease (SCD) and sickle cell traits–were the most frequently reported conditions, with prevalence estimates as high as 61%, underscoring Nigeria’s substantial disease burden. Glucose-6-phosphate dehydrogenase (G6PD) deficiency was also commonly reported, with prevalence reaching up to 60% in some populations. Congenital anomalies involving the central nervous system, musculoskeletal system, cardiovascular system, and genitourinary tract were frequently described, with reported prevalence estimates of up to 13%, 8.8%, 3% and 6.7%, respectively. Geographically, studies were disproportionately concentrated in the southern regions, while northern areas–particularly the Northeast–were markedly underrepresented. Significant regional and condition-specific knowledge gaps persist regarding genetic disorders and congenital anomalies in Nigeria, especially in the North. Strengthening surveillance systems, expanding regionally representative research, and implementing targeted public health interventions are critical to inform equitable healthcare planning and reduce disease burden.