Grammatical complexity and accuracy of Dutch school-age children with 22q11DS and children with DLD

Abstract

Title: Grammatical complexity and accuracy of Dutch school-age children with 22q11DS and children with DLD. Background: Almost all children with the 22q11.2 microdeletion syndrome (22q11DS) are delayed in language milestones and language continues to develop slowly. It is evident that these children experience persistent language difficulties, however linguistically informed descriptions of the profile of language impairment are scarce. Moreover, the language delay does not seem directly related to a mental or physical handicap, hearing loss, emotional disorder or environmental deprivation, and therefore some children with 22q11DS receive a diagnosis of DLD. Aim: In the current study, the grammatical performance of children with 22q11DS was analyzed and compared to age-related peers with DLD. Method: In a cross-sectional, observational pilot study design, 14 children with 22q11DS and 15 children with DLD, aged 6 to 10 years, performed a conversation and picture narrative task. Their elicited language was analyzed on six outcome variables, including Mean Length of Utterance in words (MLU-word), Mean Length of Five Longest Utterances (MLU5-word), and four verb-related measures: subject-verb agreement errors, past tense marker errors, dummy auxiliaries and other verb-related errors. Group differences were analyzed. Results: There were no significant differences between the grammatical complexity and accuracy measures of children with 22q11DS and children with DLD. Conclusion: The current study found no evidence of a difference in the performance of children with 22q11DS and children with DLD across grammatical complexity and accuracy measures. Recommendations: Speech-language therapists should be cautious in diagnosing children with persistent (grammatical) language delays as DLD using a language assessment only since these could be undiagnosed cases of 22q11DS. It is recommended to refer these children to a multidisciplinary team to evaluate the presence of co-occurring problems, including 22q11DS.