Computerized neurocognitive assessment in rare genetic disorders with moderate to profound intellectual disabilities: A proof of principle study

Objective: Specific knowledge on neurocognitive functioning in (syndrome based) intellectual disability (ID) is important for the assessment, treatment and support of patients in whom this condition is present. The present study investigates the applicability of computerized neurocognitive testing in patients with rare monogenetic ID disorders by (1) determining the developmental age at which the use is contributive and (2) investigating the specificity of the tests for neurocognitive functions, independent of the ID. Method: A total of 56 patients with monogenetic ID disorders, including Kleefstra Syndrome (KS; n = 24), and a contrast group of various rare disorders (n = 32) participated. Assessments included (a) the Vineland Adaptive Behavior Scale (VABS) interview to calculate developmental age and (b) four simplified subtests of the Cambridge Neuropsychological Test Automated Battery (CANTAB). A cut-off in developmental age was estimated based on the ability to complete the CANTAB-tasks. A developmental age of 2,5 years and older allows practical application in our cohort. Results: There was no significant correlation between developmental age and results on cognitive tests (range: -0,171 0,07). A between-group comparison shows a larger dropout in the KS sub cohort (based on cross tabulation) and longer latencies on the motor screening test. Conclusions: Our results indicate that simplified CANTAB tasks are suitable for application in the ID population to unravel individual neurocognitive characteristics and, hence also, syndrome specific neurocognitive features. Furthermore, successful employment of computerized testing in this complex population may be the only way to avoid the restraints of standard classificatory clinical procedures that aim at categories of patients rather than at the individual patient with its unique cognitive neuropsychiatric complexion.