Exploring the familial role of social responsiveness differences between savant and non-savant children with autism

Abstract

Savant syndrome is a phenomenon whereby individuals with cognitive impairments have one or more outstanding abilities, inconsistent with their general intellectual functioning. Approximately 50% of savant individuals have autism spectrum disorder (ASD), and 10-30% of people with ASD have savant skills. To shed additional light on this considerable overlap, we compared autistic traits as measured by the Social-Responsiveness-Scale (SRS) between 712 children with at least one reported savant skill, as determined by designated questions from the ADI-R questionnaire (savant group), and 2,032 non-savant children from the Simons-Simplex-Collection (SSC) database. We also examined SRS scores of the parents of these children and compared parent-child differences in SRS scores between the savant and non-savant groups. Savant children had significantly lower SRS scores (less deficiencies) compared to non-savant children (P < 0.05), while no such differences were observed among their parents. Further intra-familial analyses revealed weak pairwise-correlations (r = -0.015-0.141) between SRS scores of parents and their children, and significantly larger parent-child differences in standardized SRS scores within savant families (P < 0.05). These findings suggest that the less severe autistic traits among savant children with ASD compared to other people with ASD is not likely to be a familial trait.

Figure 1

Comparison of raw SRS scores between the savant and non-savant groups. Mean ± SE of SRS scores are displayed for children in the non-savant group (Dark Gray bars), children with any savant skill (Light Gray bars), as well as for children with specific savant skills (White bars). Asterisks indicate statistically significant difference between groups of specific savant skills and non-savants at (P_FDR < 0.05). (A) Total SRS scores; (B) awareness domain scores; (C) cognition domain scores; (D) communication domain scores; (E) mannerisms domain scores; (F) motivation domain scores.

Figure 2

Comparison of raw SRS scores between parents of children with ASD. Mean ± SE of SRS scores are displayed for parents of children in the non-savant group (Dark Gray bars), and in the savant group (Light Gray bars). Statistically significant differences between fathers and mothers of children with ASD are seen across all SRS domains but not in the total SRS score. (A) Total SRS scores; (B) awareness domain scores; (C) cognition domain scores; (D) communication domain scores; (E) mannerism domain scores; (F) motivation domain scores.

Figure 3

Parent-child pairwise differences of standardized SRS scores. The mean difference in standardized SRS score between children and their fathers, children and their mothers, and between fathers and mothers of these children are depicted for the non-savant group (Dark Gray bars) and savant group (Light Gray bars). (A) Total SRS scores; (B) awareness domain scores; (C) cognition domain scores; (D) communication domain scores; (E) mannerism domain scores; (F) motivation domain scores.