Children with Down syndrome exhibit unique learning characteristics that impact their educational progress. Despite this, research on effective reading interventions specifically tailored for this population remains limited. The present study aimed to find the best ways to teach teaching foundational reading skills to children with Down syndrome. Specifically, the focus was on letter-sound correspondence and the ability to identify initial sounds using pictures. Additionally, the study explored whether modifications aligned with the Down syndrome behavioral phenotype could enhance learning outcomes. Adapted versions of the Early Literacy Skills Builder (ELSB) curriculum were employed to further support children with Down syndrome. The research design utilized a single-case multiple-baseline approach across four participants in kindergarten through second grade. These participants were at the early stages of reading development and primarily communicated verbally. Despite variability and mixed trends observed during different phases, the results revealed moderate evidence of a functional relation between the ELSB: Basic Strategies version of the curriculum and the targeted reading skills. The social validity of the intervention was supported by the participants and parents reports of perceived importance and intentions to continue using the strategies. These findings hold implications for the design of effective reading interventions for children with Down syndrome and adapting existing curricula to meet their unique needs. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]