THE HERITABILITY OF STRABISMUS

The etiology of strabismus has long been observed to have a genetic co mponent. Recent advances in genetic methodology may provide insight in to the genetic basis for several types of inherited strabismus, includ ing those associated with genetic multisystem disorders such as Moebiu s syndrome, Prader-Willi syndrome, craniofacial dysostoses, and mitoch ondrial myopathies. Inheritance of primary forms of strabismus, such a s congenital ocular fibrosis, Brown syndrome and Duane syndrome, has b een reported, but less is known of the defective genetic sites. The ge netic basis for isolated strabismus that clusters in families, such as infantile esotropia syndrome, is also not yet known, but new techniqu es of molecular biology may now permit linkage detection in these fami lies. By identifying affected families, clinicians will take part in u nraveling the genetic basis of hereditary strabismus syndromes.