GENEE TIC STUDY Of' NON-ACQUIRED CHilDHOOD BLINDNESS

Abstract

To study childhood blindness, the etiology, the genetic origin and to establish their mode of inheritance a sample of 50 cases with non-acquired childhood blindness was selected. Clinical examination, consanguinity and Inbreeding coefficient studies, chromosomal analysis, pedigree construction and opthalmological examination were carried out on the cases. Chromosomal analysis and biochemical studies were limited to indicated cases. The results obtained revealed the following:

1. Congenital cataract was the most common cause of blindness

(32%).

2. The age of studied cases ranged between 11h-16 years with a mean 4.5 years. 3. Out of 50 studied cases, 40 cases (80%) developed blindness before the age of 2 years and 62.5% of these were blind since birth. 4. Male cases represented 56% of cases.

5. A positive family history of blindness was observed in 21 cases

(48.8%).

6. Parental consanguinity were extremely high among the blind cases (69.8%) with 0.043 an average inbreeding coefficient. 7. Isolated blindness was present in 19 cases (38%) only; while blindness associated with systemic manifestations constituted 62%.