The aetiology of learning disability in preschool children with special reference to preventability.

Abstract

The aims of the study were to determine the aetiology of moderate and severe learning disability in preschool children in Cape Town, to consider the causes by race and to assess the degree of preventability. All children under the age of 6 years who presented to the Developmental Assessment Clinics at the Red Cross Children's Hospital with a developmental quotient of less than 50 over a 1-year period were included. The Development Assessment Clinics form a regional multidisciplinary service for the evaluation of preschool children with development disabilities. Over the 12-month period, 232 children were identified, of whom 65% were Coloured, 32% African and the remaining 3% white. This roughly corresponds with teh breakdown of births by race in the region. Regarding the aetiology, in 45% the disability was prenatal in origin, in 17% perinatal, in 9% postnatal and in a quarter it was idiopathic. In the Coloured and white children, the cause in over a half arose prenatally and in 8.3% postnatally. In contrast, the cause in less than a third of the African cases arose in the prenatal period, but 36% resulted from perinatal complications. More of the African children had multiple disabilities and additional disabilities were more common in the perinatal and postnatal categories. Forty per cent of all cases were considered to be preventable, 16% with existing knowledge and current practice. There was no significant difference in preventability between the races.