<p>Obstructive sleep apnea is a frequently occurring sleep disorders among the individuals with Down syndrome. This is a multifactorial trait and critical problem arises owing to gene dose imbalance that causes anatomical deformities, immune system dysfunction&#xa0;and respiratory distress. Obstructive sleep apnea in turn severely affects cognitive ability and related to early onset of Alzheimer’s disease and dementia among the individuals with Down syndrome. Allelic variations of triplicated genes and their cross talk with the genes from other part of genome impose a great range of variations in phenotypic manifestation of sleep apnea in Down syndrome. Currently, pharmacological and surgical interventions are recommended to rectify this problem. In addition, attempts are being initiated to identify the genetic variations that are responsible for sleep apnea in some cases with Down syndrome in contrast to euploid controls. This comprehensive review is focussed on current understanding of cause and effects of sleep apnea in Down syndrome in compare to its prevalence in otherwise healthy euploid populations. Additionally, we discussed regarding current treatment strategy and future direction of research to understand its etiology that would help in personalised management of sleep apnea in Down syndrome.</p>