2025 American Academy of Neurology Abstract Website

Objective:

To characterize the natural history of NAA15-related neurodevelopmental disorder

Background:

NAA15 is a member of the NatA N-terminal acetyltransferase complex, which also includes the NAA10 enzymatic subunit. Individuals with variants in the NAA15 coding region develop NAA15-related neurodevelopmental syndrome, which presents with a wide array of manifestations that affect the heart, brain, musculoskeletal system, and behavioral and cognitive development.

Design/Methods:

This study is a retrospective analysis of Vineland-3 data collected from individuals with pathogenic NAA15 variants. Pathogenic variants were analyzed together and graphed by comparing Vineland component standard scores against the age at time of assessment. Further analysis was performed by filtering by sex. Scores were compared with two-tailed equal variance t-tests to compare the adaptive behavior outcomes between males and females to determine if there were sex differences. The p-value was set at .05 for all calculations. Correlation coefficients were also calculated.

Results:

27 participants (9 females and 18 males) were administered the Vineland. Ages ranged from 1 year to 24.5 years (mean = 9.0 years, standard deviation (SD) = 5.2). Average ABC score among NAA15 variants was 68.5 (SD = 22.1). This is significantly worse than the average population (mean = 100, SD = 15). Females tended to outperform males across adaptive behavior domains. These differences were not statistically significant except for in the Motor domain. Males, with the exclusion of an outlier, showed moderate linear increase in adaptive function over time,(r=0.38) whereas females appeared to show a moderate linear decay (r=-0.51).

Conclusions:

Additional longitudinal data should be collected to determine the validity of the between sex-differences and to better understand the change in adaptive behavioral outcomes of individuals with NAA15-neurodevelopmental disorder as they age.