First clinical genetic study of intellectual disability in the People's Republic of Angola

Abstract

Introduction: The American Association on Mental Retardation characterizes intellectual disability as significant limitations in intellectual functioning and adaptive behavior (practical, social, and conceptual skills), beginning before the age of 18. Objective: To characterize the causes of intellectual disability in a sample of institutionalized children at the Special School in Benguela in the People's Republic of Angola. Material and Methods: A prospective cross-sectional descriptive observational study was carried out on a population of 139 schoolchildren with intellectual disabilities. Guvtavson etiopathogenic classification was applied to define the cause. Results: Prenatal etiology was the most frequent (45.3%), followed by postnatal (29.5%) and perinatal ones (18.0%). Environmental etiology (20.9%) was the most prevalent in the prenatal category, highlighting alcohol consumption (8.6%). In the perinatal stage, hypoxia at birth (5.0%) stood out. In the postnatal stage, cerebral malaria (15.1%) was the first cause, being also the third most predominant among all categories. In addition, 80% of the cases studied had at least one relative with the same disability. In summary, 68.4% of the cases had an environmental cause, being totally preventable. Conclusions: The study corroborated that the noxas that operate in the prenatal stage affect the appearance of intellectual disability and is distinguished by positioning postnatal causes; cerebral malaria in second place. The factors of an environmental nature that operate both in the prenatal and postnatal stages are most influencing, but preventable.

Keywords

• discapacidad intelectual, retraso mental, genética/discapacidad intelectual, etiología/discapacidad intelectual, causas/retraso mental.