PREVALENCE OF PRIMARY MONOFIXATION SYNDROME IN PARENTS OF CHILDREN WITH CONGENITAL ESTOROPIA

The prevalence of primary monofixation syndrome (MFS) in the general p opulation is approximately 1%. This study was performed to determine t he prevalence of primary monofixation in biological parents of childre n with congenital esotropia. Ninety children with congenital esotropia were seen between November 1991 and June 1992 by one ophthalmologist (M.M.P.). One hundred and twenty-nine biological parents of these chil dren were screened for sensorimotor abnormalities. Twelve parents were found to have secondary MFS and were removed from the analysis. This left 78 apparently non-strabismic families consisting of a total of 11 7 parents. Seven parents were identified as having primary MFS. The pr evalence of primary MFS in this population is 9% of families and 6% of parents. Congenital esotropia is believed to be inherited in a multif actorial fashion. We believe that this increase in the prevalence of p rimary MFS compared to the general population lends support to the hyp othesis that primary MFS may be a mild (subthreshold) effect of the '' gene(s)'' that cause congenital esotropia.