Department of Psychology, Drexel University, Philadelphia, PA.
AJ Drexel Autism Institute, Philadelphia, PA.
J Dev Behav Pediatr. 2020 Apr;41(3):172-179. doi: 10.1097/DBP.0000000000000745.
The prevalence of comorbid autism spectrum disorder (ASD) in children with Down syndrome (DS) is estimated to be around 16%. This study aims to fill gaps in the literature by describing developmental and behavioral phenotypes in this group relative to those with DS or ASD in isolation.
Participants included 173 children (Mage = 73 months) with ASD, DS, or DS + ASD. Two 3 × 2 repeated-measures analyses of variance were completed with between-subject factors of the diagnostic group (DS, ASD, and DS + ASD) and within-subject factors of cognitive performance (verbal and nonverbal developmental quotient [DQ]) or ASD symptoms (social affect [SA] and restricted and repetitive behaviors [RRBs]).
Significant group-by-scale interactions were found, and pairwise comparisons revealed that for verbal DQ, DS + ASD < DS, ASD, whereas for nonverbal DQ, DS + ASD < DS < ASD. For SA, DS < DS + ASD < ASD, whereas for RRB, DS, DS + ASD < ASD.
Findings suggest greater cognitive impairment in DS + ASD on both verbal and nonverbal measures. Despite these significant cognitive challenges, ASD symptoms appeared less severe in DS + ASD relative to peers with ASD in isolation, although SA symptoms were elevated over DS-only. This unique DS + ASD presentation has important implications for early identification and intervention. Given previous research suggesting relative social strengths in DS and less severe ASD symptoms documented in this study, future research may benefit from investigating different aspects of SA (i.e., components related to reciprocal social interaction vs. social communication) in those with DS + ASD to more clearly delineate the social phenotype in this group and potentially inform intervention efforts.
唐氏综合征（DS）患儿合并孤独症谱系障碍（ASD）的患病率估计在 16%左右。本研究旨在通过描述该群体相对于单纯 DS 或 ASD 个体的发育和行为表型，填补文献中的空白。
参与者包括 173 名儿童（平均年龄=73 个月），患有 ASD、DS 或 DS+ASD。采用 3×2 重复测量方差分析，其中包括被试间因素（DS、ASD 和 DS+ASD）和内变量因素（认知表现[言语和非言语发育商数（DQ）]或 ASD 症状[社交情感（SA）和受限和重复行为（RRBs）]）。
发现存在显著的组间-组内交互作用，两两比较显示，言语 DQ 方面，DS+ASD<DS<ASD；而非言语 DQ 方面，DS+ASD<DS<ASD。在 SA 方面，DS<DS+ASD<ASD，而在 RRB 方面，DS、DS+ASD<ASD。
研究结果表明，DS+ASD 在言语和非言语方面的认知障碍更严重。尽管存在这些显著的认知挑战，但 DS+ASD 组的 ASD 症状相对于单纯 ASD 组的症状较轻，尽管 DS+ASD 组的 SA 症状高于单纯 DS 组。这种独特的 DS+ASD 表现对早期识别和干预具有重要意义。鉴于之前的研究表明 DS 存在相对的社交优势，以及本研究中记录到的 ASD 症状较轻，未来的研究可能受益于调查 DS+ASD 患者中 SA 的不同方面（即与互惠社会互动相关的成分与社会沟通），以更清楚地描绘该群体的社会表型，并可能为干预工作提供信息。
