Mean Length of Utterance as a Linguistic Marker of Expressive Language in Gujarati-Speaking Children with Down Syndrome

Abstract

Expressive language delay is a well-documented challenge in Down syndrome, yet little is known about how well Mean Length of Utterance (MLU) marks grammatical growth in Gujarati-speaking children with the condition. This cross-sectional study examined MLU as a linguistic marker of expressive language development in fifteen Gujarati-speaking children with Down syndrome, aged 5 to 10 years, divided into mild, moderate, and severe language-impairment groups of five each, based on Brown's MLU method. As the data did not meet parametric assumptions, non-parametric methods were used throughout, including descriptive statistics, the Kruskal-Wallis test, Dunn's post hoc test with Bonferroni correction, Spearman's rank correlation, and the Mann-Whitney U test. MLU differed significantly across the three severity groups (H = 12.50, p = 0.002), with the mild group showing the highest average MLU; post hoc comparisons confirmed a significant difference between the mild and severe groups (p = 0.001), though mild-moderate and moderate-severe comparisons did not reach significance. Age and MLU were strongly correlated (rho = 0.907, p < 0.001), while gender showed no significant effect (U = 19.0, p = 0.336). These findings support MLU as a meaningful, reliable marker of expressive language development in this population, particularly given its strong association with age, although its ability to differentiate moderate severity levels needs further validation in larger studies.