The role of molecular genetics in the prenatal diagnosis of retinal dystrophies

Abstract

Inherited retinal dystrophies are important causes of incurable blindness in developed countries. Advances in molecular genetics promise significant improvements in their management. Immediate benefits of present knowledge are presymptomatic and prenatal diagnosis in selected cases. To study the predictive power of these techniques a simulated genetic risk estimation was undertaken in a cone-rod retinal dystrophy pedigree known to be linked to chromosome 19. Using data on five fully informative, flanking DNA markers, phenotype was correctly assigned with only a 2% probability of error. If the two most closely linked markers were found to be uninformative, this error probability remained unchanged. Using genetic risk calculations and direct mutation detection many retinal dystrophies could now be identified by prenatal diagnosis.

Ethical issues in ocular genetics

“…Prenatal diagnosis for cone-rod retinal dystrophy, an uncommon but severe cause of early-onset blindness, carries an error of only 2% [8], and thus is lawful. However, ADRP tends to appear at a much later stage in life and progresses to total blindness over many years.…”