A battery of objective psychological tests was administered to 25 children with familial dysautonomia and to ten unaffected siblings. Although the children with dysautonomia were able to achieve, on the average, an intelligence quotient within the low average range, comparison with the unaffected siblings lings indicated significant mental impairment. Of all the subtests given, the dysautonomic children scored best in "similarities," particularly those who were nine years old or older, indicating an ability to think conceptually.Of 19 dysautonomic children, only two have been able to maintain a normal position in school. Factors associated with the disease other than intelligence have probably contributed to this poor performance.Abstract Teaser