1. A normative chart for cognitive development in a genetically selected population
- Author
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Fiksinski, A.M., Bearden, C.E., Bassett, A.S., Kahn, R.S., Zinkstok, J.R., Hooper, S.R., Tempelaar, W., McDonald-McGinn, D., Swillen, A., Emanuel, B., Morrow, B., Gur, R., Chow, E., Bree, M. van, Vermeesch, J., Warren, S., Owen, M., Amelsvoort, T. van, Eliez, S., Gothelf, D., Arango, C., Kates, W., Simon, T., Murphy, K., Repetto, G., Suner, D.H., Vicari, S., Cubells, J., Armando, M., Philip, N., Campbell, L., Garcia-Minaur, S., Schneider, M., Shashi, V., Vorstman, J., Breetvelt, E.J., Fiksinski, A.M., Bearden, C.E., Bassett, A.S., Kahn, R.S., Zinkstok, J.R., Hooper, S.R., Tempelaar, W., McDonald-McGinn, D., Swillen, A., Emanuel, B., Morrow, B., Gur, R., Chow, E., Bree, M. van, Vermeesch, J., Warren, S., Owen, M., Amelsvoort, T. van, Eliez, S., Gothelf, D., Arango, C., Kates, W., Simon, T., Murphy, K., Repetto, G., Suner, D.H., Vicari, S., Cubells, J., Armando, M., Philip, N., Campbell, L., Garcia-Minaur, S., Schneider, M., Shashi, V., Vorstman, J., and Breetvelt, E.J.
- Abstract
Item does not contain fulltext, Certain pathogenic genetic variants impact neurodevelopment and cause deviations from typical cognitive trajectories. Understanding variant-specific cognitive trajectories is clinically important for informed monitoring and identifying patients at risk for comorbid conditions. Here, we demonstrate a variant-specific normative chart for cognitive development for individuals with 22q11.2 deletion syndrome (22q11DS). We used IQ data from 1365 individuals with 22q11DS to construct variant-specific normative charts for cognitive development (Full Scale, Verbal, and Performance IQ). This allowed us to calculate Z-scores for each IQ datapoint. Then, we calculated the change between first and last available IQ assessments (delta Z-IQ-scores) for each individual with longitudinal IQ data (n = 708). We subsequently investigated whether using the variant-specific IQ-Z-scores would decrease required sample size to detect an effect with schizophrenia risk, as compared to standard IQ-scores. The mean Z-IQ-scores for FSIQ, VIQ, and PIQ were close to 0, indicating that participants had IQ-scores as predicted by the normative chart. The mean delta-Z-IQ-scores were equally close to 0, demonstrating a good fit of the normative chart and indicating that, as a group, individuals with 22q11DS show a decline in IQ-scores as they grow into adulthood. Using variant-specific IQ-Z-scores resulted in 30% decrease of required sample size, as compared to the standard IQ-based approach, to detect the association between IQ-decline and schizophrenia (p < 0.01). Our findings suggest that using variant-specific normative IQ data significantly reduces required sample size in a research context, and may facilitate a more clinically informative interpretation of IQ data. This approach allows identification of individuals that deviate from their expected, variant-specific, trajectory. This group may be at increased risk for comorbid conditions, such as schizophrenia in the case of 22q11DS.
- Published
- 2022