Children often present to the pediatric ophthalmologist because of a family history of eye disease. A common cause for such referrals is an autosomal dominant retinal dystrophy diagnosed in older family members. Clinical evaluation of the children in the family is often inconclusive because of the protean manifestations of such inherited disorders early in life.
Denaturing gradient gel electrophoresis (DGGE) is a technique which can detect single base pair changes in DNA. Using the polymerase chain reaction in combination with DGGE, a number of mutations in the peripherin gene have been found to cause autosomal dominant retinitis pigmentosa (ADRP) as well as "butterfly" pattern macular dystrophy in several large pedigrees.
We utilized DGGE to screen for mutations in peripherin in affected adults from pedigrees with ADRP and pattern macular dystrophy. Once the specific genetic defect was located in older, definitely affected family members, DNA extracted from peripheral blood was analyzed from children too young for accurate clinical diagnosis. In this way, affection status could be known with certainty and appropriate counseling given.
In one butterfly macular dystrophy family we noted that although affected children had normal macular photostress recovery times, recovery time increased with age in persons carrying the defective peripherin gene.