Sex differences in the neurodevelopment of school-age children with and without single-suture craniosynostosis

Previous studies have indicated that infants and school-age children with single-suture craniosynostosis (SSC, cases) score modestly but consistently lower than unaffected children (controls) on neurodevelopmental tests. However, sex differences in these functions rarely have been examined, and it is unknown whether potential sex differences vary by case status (cases vs. controls) or location of suture fusion. We tested 182 cases and 183 demographically matched controls at a mean age of 7.4 years. We measured intellectual abilities with the Wechsler Scale of Intelligence for Children-Fourth Edition. We assessed reading, spelling, and math with a combination of the Wide Range Assessment Test-Fourth Edition, the Test of Word Reading Efficiency, and the Comprehensive Test of Phonological Processing. Among both cases and controls, males scored lower on all measures than females with standard score differences ranging from -1.2 to -7.8 for controls (p values from < 0.001 to 0.55) and -2.3 to -8.5 for cases (p values from < 0.001 to 0.33). For all but one measure, sex differences were slightly larger for cases than controls. Among cases, males were more likely than females to have learning problems (50 vs. 30 %, respectively), with the highest level observed among males with unicoronal synostosis (86 %). Sex differences in neurodevelopmental abilities among children with SSC are substantial, but not a unique correlate of this disorder as similar differences were observed among controls. Girls and those with sagittal synostosis have the lowest risk for academic problems. Boys with unicoronal synostosis warrant close developmental surveillance.