Social functioning patterns vary across measures in children with neurofibromatosis type 1 (NF1; Glad et al., 2021) with broad psychosocial screening measures having shown no impairment (Klein-Tasman et al., 2014; Martin et al., 2012; Sangster et al., 2011) while a more specific social functioning measure indicated poorer social skills (Barton & North, 2004; Huijbregts & de Sonneville, 2011; Loitfelder et al., 2015). The current aims were to characterize caregiver-reported social skills using three different measures and determine which measure appears to best capture social difficulties for young children with NF1.

Fifty children with NF1 (31 males; M=3.96, SD=1.05) and 20 unaffected siblings (11 males; M=4.34, SD=0.88) in early childhood (ages 3-6) were rated by a caregiver on one social functioning measure (the Social Skills scale on the Social Skills Rating System (SSRS)) and two broader functioning measures that include assessment of social functioning (the Social Skills scale on the Behavior Assessment System for Children-Second Edition (BASC-2), Social Interaction and Communication domain on the Scales of Independent Behavior-Revised (SIB-R)).

For children with NF1, the SSRS mean standard score was significantly lower than the BASC-2 and SIB-R (f=-5.11, p<.001; f=-4.63, p<.001) while there was no significant difference between the BASC-2 and SIB-R. No significant differences emerged between measures for unaffected siblings. No significant group differences in mean standard score were found for the SSRS, BASC-2 or SIB-R. Fisher’s exact tests revealed the NF1 group had significantly more frequent difficulties than unaffected siblings on the BASC-2 (p=.017) but not on the SSRS or SIB-R. For both groups, Cochran’s Q tests determined a significant difference in the proportion of identified social difficulties across measures (NF1: X2(2)=16.33, p<.001; Siblings: X2(2)=9.25, p=.01). Follow up McNemar’s tests demonstrated significantly more difficulties reported on the SSRS compared to the BASC-2 for both groups (NF1: p<.001; Siblings: p=.016). Significantly more frequent difficulties were also reported on the SSRS compared to the SIB-R for the NF1 group (p=.002) but not for the unaffected siblings group. No difference in the frequency of difficulties was evident between the BASC-2 and SIB-R for either group.

Social skills difficulties appear to be best captured using the SSRS in young children, particularly for children with NF1 as this measure resulted in the lowest mean score and the greatest frequency of difficulties observed within the NF1 group. However, it is notable that group differences in comparison to unaffected siblings were not observed in mean score or frequency of difficulties, such that these young children with NF1 are not showing marked social challenges but rather, social difficulties may be mild when present at this age. Nevertheless, using a measure that specifically targets social functioning, rather than a measure where social functioning is merely a component of a broad measure, appears beneficial to capturing social difficulty. Using measures that best capture social difficulties will contribute to early identification and assessment of intervention effectiveness. Further work with additional age ranges and longitudinal trajectory is needed.