Pattern of impairments and late diagnosis of autism spectrum disorder among a sub-Saharan African clinical population of children in Nigeria

Background. Autism spectrum disorder (ASD) is a complex group of neurodevelopmental disorders. Studies conducted among Africans living outside the continent indicate that African children are more likely than Caucasian children to have a late diagnosis of ASD. There is a dearth of information on this topic among children with ASD living in Africa. Methods. To determine the pattern of impairments and age at diagnosis in ASD, sixty Nigerian children with a diagnosis of ASD were recruited from a neurodevelopmental clinic. DSM-V criteria were used to make a diagnosis of ASD, while a symptom checklist for ASD was used to determine the pattern of impairments in ASD. Results. Ages of the children ranged from 2 to 17 years with a mean age of 9.45 +/- 4.33 years with the majority of them (75%) being 12 years or younger. All the children (100%) with ASD exhibited poor eye contact, difficulty in mixing with other children and inability to consistently respond to his/ her name. More than a half of them (55%) lack verbal communication. Impairments that were uncommon are in the areas of object attachment (20.0%), odd postures (26.7%) and inappropriate facial expression (30.0%). Mean age at the observation of ASD features was 17.0 +/- 6.7 months. Mean age at diagnosis of ASD was 9.00 +/- 4.30 years. The mean time lag from a parental concern of ASD features to seeking specialist care was 85 months and to diagnosis was 91 months. Conclusions. Core symptoms/impairments of ASD are present in Nigerian children but a late diagnosis is common.