Cultural, phenotypic and genotypic characteristics of autism spectrum disorder among people of African descent: A 10 year systematic review from 2013 to 2023

Abstract

Objectives: This systematic review evaluated ASD studies conducted in Africa between 1st January 2013 and 31st July 2023.

Data Sources: Google scholar, Scopus and Medline were searched in August and September 2023

Study Selection and Extraction: Using PRISMA Guidelines, 35 studies were identified for review.

Data Synthesis: Culturally, Africans residing in all regions of the continent shared similar beliefs on the genesis of neurodevelopmental  disorders; there was a strong belief in supernatural causes such as curses, God’s will and human maleficence. Traditional and spiritual  interventions sought in tandem with conventional medicine with an aim of cure in some instances. Phenotypical presentation of ASD in  African patients did not differ from those described globally. Those with severer phenotypes, attendant complications such as convulsive  disorder and syndromic autism such as Down Syndrome were more likely to be diagnosed at an earlier age. Of the genotypic studies  undertaken, only one utilized whole exome sequencing, with rest evaluating single or multiple candidate genes or cytogenetic analysis. ASD phenotype was associated with both known and novel and genetic variations and chromosomal aberrations.

Conclusion: ASD in  Africans has similar phenotypic and genotypic features as compared to the rest of the world. Cultural beliefs on causation and prognosis  of ASD have may have an adverse impact of health outcomes. Paucity of extensive genotypic and multi-omics data impairs adequate  genotypic-phenotypic correlation of ASD among Africans.